diff --git a/.flake8 b/.flake8
deleted file mode 100644
index a27dfabab003..000000000000
--- a/.flake8
+++ /dev/null
@@ -1,130 +0,0 @@
-[flake8]
-max-line-length = 99
-exclude =
-    # These paths should be triaged and either fixed or moved to the list below.
-    devtools/shared,
-    dom/bindings/Codegen.py,
-    dom/bindings/parser/WebIDL.py,
-    dom/bindings/parser/tests/test_arraybuffer.py,
-    dom/bindings/parser/tests/test_securecontext_extended_attribute.py,
-    gfx/tests,
-    ipc/ipdl/ipdl,
-    layout/base/tests/marionette,
-    layout/reftests/border-image,
-    layout/reftests/fonts,
-    layout/reftests/w3c-css,
-    layout/style,
-    media/libdav1d/generate_source.py,
-    moz.configure,
-    netwerk/dns/prepare_tlds.py,
-    netwerk/protocol/http/make_incoming_tables.py,
-    python/l10n/fluent_migrations,
-    security/manager/ssl/tests/unit,
-    servo/components/style,
-    testing/condprofile/condprof/android.py,
-    testing/condprofile/condprof/creator.py,
-    testing/condprofile/condprof/desktop.py,
-    testing/condprofile/condprof/runner.py,
-    testing/condprofile/condprof/scenarii/heavy.py,
-    testing/condprofile/condprof/scenarii/settled.py,
-    testing/condprofile/condprof/scenarii/synced.py
-    testing/condprofile/condprof/helpers.py,
-    testing/jsshell/benchmark.py,
-    testing/marionette/mach_commands.py,
-    testing/mozharness/docs,
-    testing/mozharness/examples,
-    testing/mozharness/external_tools,
-    testing/mozharness/mach_commands.py,
-    testing/mozharness/manifestparser,
-    testing/mozharness/mozprocess,
-    testing/mozharness/setup.py,
-    testing/parse_build_tests_ccov.py,
-    testing/runtimes/writeruntimes.py,
-    testing/tools/iceserver/iceserver.py,
-    testing/tools/websocketprocessbridge/websocketprocessbridge.py,
-    toolkit/components/featuregates,
-    toolkit/content/tests/chrome/file_about_networking_wsh.py,
-    toolkit/library/build/dependentlibs.py,
-    toolkit/locales/generate_update_locale.py,
-    toolkit/mozapps,
-    toolkit/moz.configure,
-    toolkit/nss.configure,
-
-    # mako files are not really python files
-    *.mako.py,
-
-    # These paths are intentionally excluded (not necessarily for good reason).
-    build/moz.configure/*.configure,
-    build/pymake/,
-    browser/extensions/mortar/ppapi/,
-    browser/moz.configure,
-    dom/canvas/test/webgl-conf/checkout/closure-library/,
-    editor/libeditor/tests/browserscope/,
-    intl/icu/,
-    ipc/chromium/src/third_party/,
-    js/*.configure,
-    gfx/angle/,
-    gfx/harfbuzz,
-    gfx/skia/,
-    memory/moz.configure,
-    mobile/android/*.configure,
-    node_modules,
-    python/mozbuild/mozbuild/test/configure/data,
-    security/nss/,
-    testing/marionette/harness/marionette_harness/runner/mixins,
-    testing/marionette/harness/marionette_harness/tests,
-    testing/mochitest/pywebsocket3,
-    testing/mozharness/configs/test/test_malformed.py,
-    testing/web-platform/tests,
-    tools/lint/test/files,
-    tools/crashreporter/*.configure,
-    .ycm_extra_conf.py,
-
-# See:
-#   - http://flake8.pycqa.org/en/latest/user/error-codes.html
-#   - http://pep8.readthedocs.io/en/latest/intro.html#configuration
-ignore =
-    # These should be triaged and either fixed or moved to the list below.
-    W605, W606,
-    # These are intentionally disabled (not necessarily for good reason).
-    #   F723: syntax error in type comment
-    #       text contains quotes which breaks our custom JSON formatter
-    F723, E704, E741,
-
-    # black is already in charge of formatting, no need to start a formatter
-    # battle here
-    E1, W1, E2, W2, E3, W3, E4, W4, E5, W5
-
-per-file-ignores =
-    # These paths are intentionally excluded.
-    ipc/ipdl/*: F403, F405
-    layout/tools/reftest/selftest/conftest.py: F811
-    # cpp_eclipse has a lot of multi-line embedded XML which exceeds line length
-    python/mozbuild/mozbuild/backend/cpp_eclipse.py: E501
-    testing/firefox-ui/**/__init__.py: F401
-    testing/marionette/**/__init__.py: F401
-    testing/mochitest/tests/python/conftest.py: F811
-    testing/mozbase/manifestparser/tests/test_filters.py: E731
-    testing/mozbase/mozlog/tests/test_formatters.py: E501
-    testing/mozharness/configs/*: E124, E127, E128, E131, E231, E261, E265, E266, E501, W391
-
-    # These paths contain Python-2 only syntax which cause errors since flake8
-    # is run with Python 3.
-    build/compare-mozconfig/compare-mozconfigs.py: F821
-    build/midl.py: F821
-    build/pgo/genpgocert.py: F821
-    config/MozZipFile.py: F821
-    config/check_source_count.py: F821
-    config/tests/unitMozZipFile.py: F821
-    ipc/pull-chromium.py: F633
-    js/src/**: F633, F821
-    python/mozbuild/mozbuild/action/dump_env.py: F821
-    python/mozbuild/mozbuild/dotproperties.py: F821
-    python/mozbuild/mozbuild/testing.py: F821
-    python/mozbuild/mozbuild/util.py: F821
-    testing/mozharness/mozharness/mozilla/testing/android.py: F821
-    testing/mochitest/runtests.py: F821
-
-builtins =
-    # For GDB extensions
-    gdb
diff --git a/.hgignore b/.hgignore
index f3b1e406eb54..21559a945dfd 100644
--- a/.hgignore
+++ b/.hgignore
@@ -225,6 +225,9 @@ _OPT\.OBJ/
 # Unit test
 \.pytest_cache/
 
+# Ruff
+\.ruff_cache/
+
 # Ignore files created when running a reftest.
 ^lextab.py$
 
diff --git a/docs/code-quality/index.rst b/docs/code-quality/index.rst
index 305d5719a021..d45ce7e06be3 100644
--- a/docs/code-quality/index.rst
+++ b/docs/code-quality/index.rst
@@ -90,11 +90,11 @@ In this document, we try to list these all tools.
      - Meta bug
      - More info
      - Upstream
-   * - Flake8
-     - Yes (with `autopep8 <https://github.com/hhatto/autopep8>`_)
-     - `bug 1155970 <https://bugzilla.mozilla.org/show_bug.cgi?id=1155970>`__
-     - :ref:`Flake8`
-     - http://flake8.pycqa.org/
+   * - ruff
+     - Yes
+     - `bug 1811850 <https://bugzilla.mozilla.org/show_bug.cgi?id=1811850>`__
+     - :ref:`ruff`
+     - https://github.com/charliermarsh/ruff
    * - black
      - Yes
      - `bug 1555560 <https://bugzilla.mozilla.org/show_bug.cgi?id=1555560>`__
@@ -105,12 +105,6 @@ In this document, we try to list these all tools.
      - `bug 1623024 <https://bugzilla.mozilla.org/show_bug.cgi?id=1623024>`__
      - :ref:`pylint`
      - https://www.pylint.org/
-   * - Python 2/3 compatibility check
-     -
-     - `bug 1496527 <https://bugzilla.mozilla.org/show_bug.cgi?id=1496527>`__
-     - :ref:`Python 2/3 compatibility check`
-     -
-
 
 .. list-table:: Rust
    :widths: 20 20 20 20 20
diff --git a/docs/code-quality/lint/linters/flake8.rst b/docs/code-quality/lint/linters/flake8.rst
deleted file mode 100644
index 0e46d33ab026..000000000000
--- a/docs/code-quality/lint/linters/flake8.rst
+++ /dev/null
@@ -1,46 +0,0 @@
-Flake8
-======
-
-`Flake8 <https://flake8.pycqa.org/en/latest/index.html>`__ is a popular lint wrapper for python. Under the hood, it runs three other tools and
-combines their results:
-
-* `pep8 <http://pep8.readthedocs.io/en/latest/>`__ for checking style
-* `pyflakes <https://github.com/pyflakes/pyflakes>`__ for checking syntax
-* `mccabe <https://github.com/pycqa/mccabe>`__ for checking complexity
-
-
-Run Locally
------------
-
-The mozlint integration of flake8 can be run using mach:
-
-.. parsed-literal::
-
-    $ mach lint --linter flake8 <file paths>
-
-Alternatively, omit the ``--linter flake8`` and run all configured linters, which will include
-flake8.
-
-
-Configuration
--------------
-
-Path configuration is defined in the root `.flake8`_ file. Please update this file rather than
-``tools/lint/flake8.yml`` if you need to exclude a new path. For an overview of the supported
-configuration, see `flake8's documentation`_.
-
-.. _.flake8: https://searchfox.org/mozilla-central/source/.flake8
-.. _flake8's documentation: https://flake8.pycqa.org/en/latest/user/configuration.html
-
-Autofix
--------
-
-The flake8 linter provides a ``--fix`` option. It is based on `autopep8 <https://github.com/hhatto/autopep8>`__.
-Please note that autopep8 does NOT fix all issues reported by flake8.
-
-
-Sources
--------
-
-* `Configuration (YAML) <https://searchfox.org/mozilla-central/source/tools/lint/flake8.yml>`_
-* `Source <https://searchfox.org/mozilla-central/source/tools/lint/python/flake8.py>`_
diff --git a/docs/code-quality/lint/linters/ruff.rst b/docs/code-quality/lint/linters/ruff.rst
new file mode 100644
index 000000000000..359e8dcbf686
--- /dev/null
+++ b/docs/code-quality/lint/linters/ruff.rst
@@ -0,0 +1,44 @@
+Ruff
+====
+
+`Ruff <https://github.com/charliermarsh/ruff>`_ is an extremely fast Python
+linter and formatter, written in Rust. It can process all of mozilla-central in
+under a second, and implements rule sets from a large array of Python linters
+and formatters, including:
+
+* flake8 (pycodestyle, pyflakes and mccabe)
+* isort
+* pylint
+* pyupgrade
+* and many many more!
+
+Run Locally
+-----------
+
+The mozlint integration of ruff can be run using mach:
+
+.. parsed-literal::
+
+   $ mach lint --linter ruff <file paths>
+
+
+Configuration
+-------------
+
+Ruff is configured in the root `pyproject.toml`_ file. Additionally, ruff will
+pick up any ``pyproject.toml`` or ``ruff.toml`` files in subdirectories. The
+settings in these files will only apply to files contained within these
+subdirs. For more details on configuration discovery, see the `configuration
+documentation`_.
+
+For a list of options, see the `settings documentation`_.
+
+Sources
+-------
+
+* `Configuration (YAML) <https://searchfox.org/mozilla-central/source/tools/lint/ruff.yml>`_
+* `Source <https://searchfox.org/mozilla-central/source/tools/lint/python/ruff.py>`_
+
+.. _pyproject.toml: https://searchfox.org/mozilla-central/source/pyproject.toml
+.. _configuration documentation: https://beta.ruff.rs/docs/configuration/
+.. _settings documentation: https://beta.ruff.rs/docs/settings/
diff --git a/moz.build b/moz.build
index 80e23e9e7c07..e33ad8e4a082 100644
--- a/moz.build
+++ b/moz.build
@@ -35,6 +35,9 @@ with Files("docs/**"):
 with Files("mach*"):
     BUG_COMPONENT = ("Firefox Build System", "Mach Core")
 
+with Files("pyproject.toml"):
+    BUG_COMPONENT = ("Developer Infrastructure", "Lint and Formatting")
+
 with Files("*moz*"):
     BUG_COMPONENT = ("Firefox Build System", "General")
 
diff --git a/pyproject.toml b/pyproject.toml
new file mode 100644
index 000000000000..bfc656b9668d
--- /dev/null
+++ b/pyproject.toml
@@ -0,0 +1,127 @@
+[tool.ruff]
+line-length = 99
+# See https://beta.ruff.rs/docs/rules/ for a full list of rules.
+select = [
+  "E", "W",    # pycodestyle
+  "F",         # pyflakes
+]
+ignore = [
+  # These should be triaged and either fixed or moved to the list below.
+  "E713", "E714", "W605",
+
+  # These are intentionally ignored (not necessarily for good reason).
+  "E741",
+
+  # These are handled by black.
+  "E1", "E4", "E5", "W2", "W5"
+]
+builtins = ["gdb"]
+exclude = [
+  # These paths should be triaged and either fixed or moved to the list below.
+  "devtools/shared",
+  "dom/bindings/Codegen.py",
+  "dom/bindings/parser/WebIDL.py",
+  "dom/bindings/parser/tests/test_arraybuffer.py",
+  "dom/bindings/parser/tests/test_securecontext_extended_attribute.py",
+  "gfx/tests",
+  "ipc/ipdl/ipdl",
+  "layout/base/tests/marionette",
+  "layout/reftests/border-image",
+  "layout/reftests/fonts",
+  "layout/reftests/w3c-css",
+  "layout/style",
+  "media/libdav1d/generate_source.py",
+  "moz.configure",
+  "netwerk/dns/prepare_tlds.py",
+  "netwerk/protocol/http/make_incoming_tables.py",
+  "python/l10n/fluent_migrations",
+  "security/manager/ssl/tests/unit",
+  "servo/components/style",
+  "testing/condprofile/condprof/android.py",
+  "testing/condprofile/condprof/creator.py",
+  "testing/condprofile/condprof/desktop.py",
+  "testing/condprofile/condprof/runner.py",
+  "testing/condprofile/condprof/scenarii/heavy.py",
+  "testing/condprofile/condprof/scenarii/settled.py",
+  "testing/condprofile/condprof/scenarii/synced.p",
+  "testing/condprofile/condprof/helpers.py",
+  "testing/jsshell/benchmark.py",
+  "testing/marionette/mach_commands.py",
+  "testing/mozharness/docs",
+  "testing/mozharness/examples",
+  "testing/mozharness/external_tools",
+  "testing/mozharness/mach_commands.py",
+  "testing/mozharness/manifestparser",
+  "testing/mozharness/mozprocess",
+  "testing/mozharness/setup.py",
+  "testing/parse_build_tests_ccov.py",
+  "testing/runtimes/writeruntimes.py",
+  "testing/tools/iceserver/iceserver.py",
+  "testing/tools/websocketprocessbridge/websocketprocessbridge.py",
+  "toolkit/components/featuregates",
+  "toolkit/content/tests/chrome/file_about_networking_wsh.py",
+  "toolkit/library/build/dependentlibs.py",
+  "toolkit/locales/generate_update_locale.py",
+  "toolkit/mozapps",
+  "toolkit/moz.configure",
+  "toolkit/nss.configure",
+
+  # mako files are not really python files
+  "*.mako.py",
+
+  # These paths are intentionally excluded (not necessarily for good reason).
+  "build/moz.configure/*.configure",
+  "build/pymake/",
+  "browser/extensions/mortar/ppapi/",
+  "browser/moz.configure",
+  "dom/canvas/test/webgl-conf/checkout/closure-library/",
+  "editor/libeditor/tests/browserscope/",
+  "intl/icu/",
+  "ipc/chromium/src/third_party/",
+  "js/*.configure",
+  "gfx/angle/",
+  "gfx/harfbuzz",
+  "gfx/skia/",
+  "memory/moz.configure",
+  "mobile/android/*.configure",
+  "node_modules",
+  "python/mozbuild/mozbuild/test/configure/data",
+  "security/nss/",
+  "testing/marionette/harness/marionette_harness/runner/mixins",
+  "testing/marionette/harness/marionette_harness/tests",
+  "testing/mochitest/pywebsocket3",
+  "testing/mozharness/configs/test/test_malformed.py",
+  "testing/web-platform/tests",
+  "tools/lint/test/files",
+  "tools/crashreporter/*.configure",
+  ".ycm_extra_conf.py",
+]
+
+[tool.ruff.per-file-ignores]
+# These paths are intentionally excluded.
+"ipc/ipdl/*" = ["F403", "F405"]
+"layout/tools/reftest/selftest/conftest.py" = ["F811"]
+# cpp_eclipse has a lot of multi-line embedded XML which exceeds line length
+"python/mozbuild/mozbuild/backend/cpp_eclipse.py" = ["E501"]
+"testing/firefox-ui/**/__init__.py" = ["F401"]
+"testing/marionette/**/__init__.py" = ["F401"]
+"testing/mochitest/tests/python/conftest.py" = ["F811"]
+"testing/mozbase/manifestparser/tests/test_filters.py" = ["E731"]
+"testing/mozbase/mozlog/tests/test_formatters.py" = ["E501"]
+"testing/mozharness/configs/*" = ["E501"]
+"**/*.configure" = ["F821"]
+# These paths contain Python-2 only syntax.
+"build/compare-mozconfig/compare-mozconfigs.py" = ["F821"]
+"build/midl.py" = ["F821"]
+"build/pgo/genpgocert.py" = ["F821"]
+"config/MozZipFile.py" = ["F821"]
+"config/check_source_count.py" = ["F821"]
+"config/tests/unitMozZipFile.py" = ["F821"]
+"ipc/pull-chromium.py" = ["F633"]
+"js/src/**" = ["F633", "F821"]
+"python/mozbuild/mozbuild/action/dump_env.py" = ["F821"]
+"python/mozbuild/mozbuild/dotproperties.py" = ["F821"]
+"python/mozbuild/mozbuild/testing.py" = ["F821"]
+"python/mozbuild/mozbuild/util.py" = ["F821"]
+"testing/mozharness/mozharness/mozilla/testing/android.py" = ["F821"]
+"testing/mochitest/runtests.py" = ["F821"]
diff --git a/python/gdbpp/gdbpp/__init__.py b/python/gdbpp/gdbpp/__init__.py
index 7a7681aa6de3..376061b679e9 100644
--- a/python/gdbpp/gdbpp/__init__.py
+++ b/python/gdbpp/gdbpp/__init__.py
@@ -20,12 +20,12 @@ class GeckoPrettyPrinter(object):
         return wrapped
 
 
-import gdbpp.enumset  # NOQA: F401
-import gdbpp.linkedlist  # NOQA: F401
-import gdbpp.owningthread  # NOQA: F401
-import gdbpp.smartptr  # NOQA: F401
-import gdbpp.string  # NOQA: F401
-import gdbpp.tarray  # NOQA: F401
-import gdbpp.thashtable  # NOQA: F401
+import gdbpp.enumset  # noqa: F401
+import gdbpp.linkedlist  # noqa: F401
+import gdbpp.owningthread  # noqa: F401
+import gdbpp.smartptr  # noqa: F401
+import gdbpp.string  # noqa: F401
+import gdbpp.tarray  # noqa: F401
+import gdbpp.thashtable  # noqa: F401
 
 gdb.printing.register_pretty_printer(None, GeckoPrettyPrinter.pp)
diff --git a/taskcluster/ci/source-test/mozlint.yml b/taskcluster/ci/source-test/mozlint.yml
index c3ab520672f6..6075ebc2e915 100644
--- a/taskcluster/ci/source-test/mozlint.yml
+++ b/taskcluster/ci/source-test/mozlint.yml
@@ -242,20 +242,6 @@ mscom-init:
             - '**/*.h'
             - 'tools/lint/mscom-init.yml'
 
-py-flake8:
-    description: flake8 run over the gecko codebase
-    treeherder:
-        symbol: py(f8)
-    run:
-        mach: lint -v -l flake8 -f treeherder -f json:/builds/worker/mozlint.json *
-    when:
-        files-changed:
-            - '**/*.py'
-            - '**/.flake8'
-            - 'tools/lint/flake8.yml'
-            # moz.configure files are also Python files.
-            - '**/*.configure'
-
 py-black:
     description: black run over the gecko codebase
     treeherder:
@@ -272,6 +258,22 @@ py-black:
             - 'pyproject.toml'
             - 'tools/lint/black.yml'
 
+py-ruff:
+    description: Run ruff over the gecko codebase
+    treeherder:
+        symbol: py(ruff)
+    run:
+        mach: lint -v -l ruff -f treeherder -f json:/builds/worker/mozlint.json *
+    when:
+        files-changed:
+            - '**/*.py'
+            - '**/*.configure'
+            - '**/.ruff.toml'
+            - 'pyproject.toml'
+            - 'tools/lint/ruff.yml'
+            - 'tools/lint/python/ruff.py'
+            - 'tools/lint/python/ruff_requirements.txt'
+
 py-pylint:
     description: pylint run over the gecko codebase
     treeherder:
diff --git a/tools/lint/file-whitespace.yml b/tools/lint/file-whitespace.yml
index e598a28414a0..2e9035da5899 100644
--- a/tools/lint/file-whitespace.yml
+++ b/tools/lint/file-whitespace.yml
@@ -3,9 +3,9 @@ file-whitespace:
     description: File content sanity check
     include:
         - .
-        - tools/lint/python/flake8_requirements.txt
         - tools/lint/python/pylint_requirements.txt
         - tools/lint/python/black_requirements.txt
+        - tools/lint/python/ruff_requirements.txt
         - tools/lint/rst/requirements.txt
         - tools/lint/tox/tox_requirements.txt
         - tools/lint/spell/codespell_requirements.txt
diff --git a/tools/lint/flake8.yml b/tools/lint/flake8.yml
deleted file mode 100644
index 11d31932717c..000000000000
--- a/tools/lint/flake8.yml
+++ /dev/null
@@ -1,15 +0,0 @@
----
-flake8:
-    description: Python linter
-    # Excludes should be added to topsrcdir/.flake8.
-    exclude: []
-    # The configure option is used by the build system
-    extensions: ['configure', 'py']
-    support-files:
-        - '**/.flake8'
-        - 'tools/lint/python/flake8*'
-    # Rules that should result in warnings rather than errors.
-    warning-rules: []
-    type: external
-    payload: python.flake8:lint
-    setup: python.flake8:setup
diff --git a/tools/lint/python/flake8.py b/tools/lint/python/flake8.py
deleted file mode 100644
index 88fec87822dd..000000000000
--- a/tools/lint/python/flake8.py
+++ /dev/null
@@ -1,215 +0,0 @@
-# This Source Code Form is subject to the terms of the Mozilla Public
-# License, v. 2.0. If a copy of the MPL was not distributed with this
-# file, You can obtain one at http://mozilla.org/MPL/2.0/.
-
-import json
-import os
-import platform
-import subprocess
-import sys
-
-import mozfile
-import mozpack.path as mozpath
-from mozlint import result
-from mozlint.pathutils import expand_exclusions
-
-here = os.path.abspath(os.path.dirname(__file__))
-FLAKE8_REQUIREMENTS_PATH = os.path.join(here, "flake8_requirements.txt")
-
-FLAKE8_NOT_FOUND = """
-Could not find flake8! Install flake8 and try again.
-
-    $ pip install -U --require-hashes -r {}
-""".strip().format(
-    FLAKE8_REQUIREMENTS_PATH
-)
-
-
-FLAKE8_INSTALL_ERROR = """
-Unable to install correct version of flake8
-Try to install it manually with:
-    $ pip install -U --require-hashes -r {}
-""".strip().format(
-    FLAKE8_REQUIREMENTS_PATH
-)
-
-LINE_OFFSETS = {
-    # continuation line under-indented for hanging indent
-    "E121": (-1, 2),
-    # continuation line missing indentation or outdented
-    "E122": (-1, 2),
-    # continuation line over-indented for hanging indent
-    "E126": (-1, 2),
-    # continuation line over-indented for visual indent
-    "E127": (-1, 2),
-    # continuation line under-indented for visual indent
-    "E128": (-1, 2),
-    # continuation line unaligned for hanging indend
-    "E131": (-1, 2),
-    # expected 1 blank line, found 0
-    "E301": (-1, 2),
-    # expected 2 blank lines, found 1
-    "E302": (-2, 3),
-}
-"""Maps a flake8 error to a lineoffset tuple.
-
-The offset is of the form (lineno_offset, num_lines) and is passed
-to the lineoffset property of an `Issue`.
-"""
-
-
-def default_bindir():
-    # We use sys.prefix to find executables as that gets modified with
-    # virtualenv's activate_this.py, whereas sys.executable doesn't.
-    if platform.system() == "Windows":
-        return os.path.join(sys.prefix, "Scripts")
-    else:
-        return os.path.join(sys.prefix, "bin")
-
-
-class NothingToLint(Exception):
-    """Exception used to bail out of flake8's internals if all the specified
-    files were excluded.
-    """
-
-
-def setup(root, **lintargs):
-    virtualenv_manager = lintargs["virtualenv_manager"]
-    try:
-        virtualenv_manager.install_pip_requirements(
-            FLAKE8_REQUIREMENTS_PATH, quiet=True
-        )
-    except subprocess.CalledProcessError:
-        print(FLAKE8_INSTALL_ERROR)
-        return 1
-
-
-def lint(paths, config, **lintargs):
-
-    root = lintargs["root"]
-    virtualenv_bin_path = lintargs.get("virtualenv_bin_path")
-    config_path = os.path.join(root, ".flake8")
-
-    results = run(paths, config, **lintargs)
-    fixed = 0
-
-    if lintargs.get("fix"):
-        # fix and run again to count remaining issues
-        fixed = len(results)
-        fix_cmd = [
-            os.path.join(virtualenv_bin_path or default_bindir(), "autopep8"),
-            "--global-config",
-            config_path,
-            "--in-place",
-            "--recursive",
-        ]
-
-        if config.get("exclude"):
-            fix_cmd.extend(["--exclude", ",".join(config["exclude"])])
-
-        subprocess.call(fix_cmd + paths)
-
-        results = run(paths, config, **lintargs)
-
-        fixed = fixed - len(results)
-
-    return {"results": results, "fixed": fixed}
-
-
-def run(paths, config, **lintargs):
-    from flake8 import __version__ as flake8_version
-    from flake8.main.application import Application
-
-    log = lintargs["log"]
-    root = lintargs["root"]
-    config_path = os.path.join(root, ".flake8")
-
-    # Run flake8.
-    app = Application()
-    log.debug("flake8 version={}".format(flake8_version))
-
-    output_file = mozfile.NamedTemporaryFile(mode="r")
-    flake8_cmd = [
-        "--config",
-        config_path,
-        "--output-file",
-        output_file.name,
-        "--format",
-        '{"path":"%(path)s","lineno":%(row)s,'
-        '"column":%(col)s,"rule":"%(code)s","message":"%(text)s"}',
-        "--filename",
-        ",".join(["*.{}".format(e) for e in config["extensions"]]),
-    ]
-    log.debug("Command: {}".format(" ".join(flake8_cmd)))
-
-    orig_make_file_checker_manager = app.make_file_checker_manager
-
-    def wrap_make_file_checker_manager(self):
-        """Flake8 is very inefficient when it comes to applying exclusion
-        rules, using `expand_exclusions` to turn directories into a list of
-        relevant python files is an order of magnitude faster.
-
-        Hooking into flake8 here also gives us a convenient place to merge the
-        `exclude` rules specified in the root .flake8 with the ones added by
-        tools/lint/mach_commands.py.
-        """
-        # Ignore exclude rules if `--no-filter` was passed in.
-        config.setdefault("exclude", [])
-        if lintargs.get("use_filters", True):
-            config["exclude"].extend(map(mozpath.normpath, self.options.exclude))
-
-        # Since we use the root .flake8 file to store exclusions, we haven't
-        # properly filtered the paths through mozlint's `filterpaths` function
-        # yet. This mimics that though there could be other edge cases that are
-        # different. Maybe we should call `filterpaths` directly, though for
-        # now that doesn't appear to be necessary.
-        filtered = [
-            p for p in paths if not any(p.startswith(e) for e in config["exclude"])
-        ]
-
-        self.options.filenames = self.options.filenames + list(
-            expand_exclusions(filtered, config, root)
-        )
-
-        if not self.options.filenames:
-            raise NothingToLint
-        return orig_make_file_checker_manager()
-
-    app.make_file_checker_manager = wrap_make_file_checker_manager.__get__(
-        app, Application
-    )
-
-    # Make sure to run from repository root so exclusions are joined to the
-    # repository root and not the current working directory.
-    oldcwd = os.getcwd()
-    os.chdir(root)
-    try:
-        app.run(flake8_cmd)
-    except NothingToLint:
-        pass
-    finally:
-        os.chdir(oldcwd)
-
-    results = []
-
-    WARNING_RULES = set(config.get("warning-rules", []))
-
-    def process_line(line):
-        # Escape slashes otherwise JSON conversion will not work
-        line = line.replace("\\", "\\\\")
-        try:
-            res = json.loads(line)
-        except ValueError:
-            print("Non JSON output from linter, will not be processed: {}".format(line))
-            return
-
-        if res.get("code") in LINE_OFFSETS:
-            res["lineoffset"] = LINE_OFFSETS[res["code"]]
-
-        if res["rule"] in WARNING_RULES:
-            res["level"] = "warning"
-
-        results.append(result.from_config(config, **res))
-
-    list(map(process_line, output_file.readlines()))
-    return results
diff --git a/tools/lint/python/flake8_requirements.in b/tools/lint/python/flake8_requirements.in
deleted file mode 100644
index 0a9262b9c6e2..000000000000
--- a/tools/lint/python/flake8_requirements.in
+++ /dev/null
@@ -1,4 +0,0 @@
-flake8==5.0.4
-zipp==0.5
-autopep8==1.7.0
-typing-extensions==3.10.0.2
diff --git a/tools/lint/python/flake8_requirements.txt b/tools/lint/python/flake8_requirements.txt
deleted file mode 100644
index 36879d20c839..000000000000
--- a/tools/lint/python/flake8_requirements.txt
+++ /dev/null
@@ -1,41 +0,0 @@
-#
-# This file is autogenerated by pip-compile with python 3.10
-# To update, run:
-#
-#    pip-compile --generate-hashes tools/lint/python/flake8_requirements.in
-#
-autopep8==1.7.0 \
-    --hash=sha256:6f09e90a2be784317e84dc1add17ebfc7abe3924239957a37e5040e27d812087 \
-    --hash=sha256:ca9b1a83e53a7fad65d731dc7a2a2d50aa48f43850407c59f6a1a306c4201142
-    # via -r tools/lint/python/flake8_requirements.in
-flake8==5.0.4 \
-    --hash=sha256:6fbe320aad8d6b95cec8b8e47bc933004678dc63095be98528b7bdd2a9f510db \
-    --hash=sha256:7a1cf6b73744f5806ab95e526f6f0d8c01c66d7bbe349562d22dfca20610b248
-    # via -r tools/lint/python/flake8_requirements.in
-mccabe==0.7.0 \
-    --hash=sha256:348e0240c33b60bbdf4e523192ef919f28cb2c3d7d5c7794f74009290f236325 \
-    --hash=sha256:6c2d30ab6be0e4a46919781807b4f0d834ebdd6c6e3dca0bda5a15f863427b6e
-    # via flake8
-pycodestyle==2.9.1 \
-    --hash=sha256:2c9607871d58c76354b697b42f5d57e1ada7d261c261efac224b664affdc5785 \
-    --hash=sha256:d1735fc58b418fd7c5f658d28d943854f8a849b01a5d0a1e6f3f3fdd0166804b
-    # via
-    #   autopep8
-    #   flake8
-pyflakes==2.5.0 \
-    --hash=sha256:4579f67d887f804e67edb544428f264b7b24f435b263c4614f384135cea553d2 \
-    --hash=sha256:491feb020dca48ccc562a8c0cbe8df07ee13078df59813b83959cbdada312ea3
-    # via flake8
-toml==0.10.2 \
-    --hash=sha256:806143ae5bfb6a3c6e736a764057db0e6a0e05e338b5630894a5f779cabb4f9b \
-    --hash=sha256:b3bda1d108d5dd99f4a20d24d9c348e91c4db7ab1b749200bded2f839ccbe68f
-    # via autopep8
-typing-extensions==3.10.0.2 \
-    --hash=sha256:49f75d16ff11f1cd258e1b988ccff82a3ca5570217d7ad8c5f48205dd99a677e \
-    --hash=sha256:d8226d10bc02a29bcc81df19a26e56a9647f8b0a6d4a83924139f4a8b01f17b7 \
-    --hash=sha256:f1d25edafde516b146ecd0613dabcc61409817af4766fbbcfb8d1ad4ec441a34
-    # via -r tools/lint/python/flake8_requirements.in
-zipp==0.5 \
-    --hash=sha256:46dfd547d9ccbf8bdc26ecea52818046bb28509f12bb6a0de1cd66ab06e9a9be \
-    --hash=sha256:d7ac25f895fb65bff937b381353c14eb1fa23d35f40abd72a5342cd57eb57fd1
-    # via -r tools/lint/python/flake8_requirements.in
diff --git a/tools/lint/python/ruff.py b/tools/lint/python/ruff.py
new file mode 100644
index 000000000000..93916463fa00
--- /dev/null
+++ b/tools/lint/python/ruff.py
@@ -0,0 +1,177 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+import json
+import os
+import platform
+import re
+import signal
+import subprocess
+import sys
+from pathlib import Path
+
+import mozfile
+from mozlint import result
+from mozprocess.processhandler import ProcessHandler
+
+here = os.path.abspath(os.path.dirname(__file__))
+RUFF_REQUIREMENTS_PATH = os.path.join(here, "ruff_requirements.txt")
+
+RUFF_NOT_FOUND = """
+Could not find ruff! Install ruff and try again.
+
+    $ pip install -U --require-hashes -r {}
+""".strip().format(
+    RUFF_REQUIREMENTS_PATH
+)
+
+
+RUFF_INSTALL_ERROR = """
+Unable to install correct version of ruff!
+Try to install it manually with:
+    $ pip install -U --require-hashes -r {}
+""".strip().format(
+    RUFF_REQUIREMENTS_PATH
+)
+
+
+def default_bindir():
+    # We use sys.prefix to find executables as that gets modified with
+    # virtualenv's activate_this.py, whereas sys.executable doesn't.
+    if platform.system() == "Windows":
+        return os.path.join(sys.prefix, "Scripts")
+    else:
+        return os.path.join(sys.prefix, "bin")
+
+
+def get_ruff_version(binary):
+    """
+    Returns found binary's version
+    """
+    try:
+        output = subprocess.check_output(
+            [binary, "--version"],
+            stderr=subprocess.STDOUT,
+            text=True,
+        )
+    except subprocess.CalledProcessError as e:
+        output = e.output
+
+    matches = re.match(r"ruff ([0-9\.]+)", output)
+    if matches:
+        return matches[1]
+    print("Error: Could not parse the version '{}'".format(output))
+
+
+def setup(root, log, **lintargs):
+    virtualenv_bin_path = lintargs.get("virtualenv_bin_path")
+    binary = mozfile.which("ruff", path=(virtualenv_bin_path, default_bindir()))
+
+    if binary and os.path.isfile(binary):
+        log.debug(f"Looking for ruff at {binary}")
+        version = get_ruff_version(binary)
+        versions = [
+            line.split()[0].strip()
+            for line in open(RUFF_REQUIREMENTS_PATH).readlines()
+            if line.startswith("ruff==")
+        ]
+        if [f"ruff=={version}"] == versions:
+            log.debug("ruff is present with expected version {}".format(version))
+            return 0
+        else:
+            log.debug("ruff is present but unexpected version {}".format(version))
+
+    virtualenv_manager = lintargs["virtualenv_manager"]
+    try:
+        virtualenv_manager.install_pip_requirements(RUFF_REQUIREMENTS_PATH, quiet=True)
+    except subprocess.CalledProcessError:
+        print(RUFF_INSTALL_ERROR)
+        return 1
+
+
+class RuffProcess(ProcessHandler):
+    def __init__(self, config, *args, **kwargs):
+        self.config = config
+        self.stderr = []
+        kwargs["stream"] = False
+        kwargs["universal_newlines"] = True
+        kwargs["processStderrLine"] = lambda line: print(line, file=sys.stderr)
+        ProcessHandler.__init__(self, *args, **kwargs)
+
+    def run(self, *args, **kwargs):
+        orig = signal.signal(signal.SIGINT, signal.SIG_IGN)
+        ProcessHandler.run(self, *args, **kwargs)
+        signal.signal(signal.SIGINT, orig)
+
+
+def run_process(config, cmd):
+    proc = RuffProcess(config, cmd)
+    proc.run()
+    try:
+        proc.wait()
+    except KeyboardInterrupt:
+        proc.kill()
+
+    return "\n".join(proc.output)
+
+
+def lint(paths, config, log, **lintargs):
+    fixed = 0
+    results = []
+
+    if not paths:
+        return {"results": results, "fixed": fixed}
+
+    # Currently ruff only lints non `.py` files if they are explicitly passed
+    # in. So we need to find any non-py files manually. This can be removed
+    # after https://github.com/charliermarsh/ruff/issues/3410 is fixed.
+    exts = [e for e in config["extensions"] if e != "py"]
+    non_py_files = []
+    for path in paths:
+        p = Path(path)
+        if not p.is_dir():
+            continue
+        for ext in exts:
+            non_py_files.extend([str(f) for f in p.glob(f"**/*.{ext}")])
+
+    args = ["ruff", "check", "--force-exclude"] + paths + non_py_files
+
+    if config["exclude"]:
+        args.append(f"--extend-exclude={','.join(config['exclude'])}")
+
+    if lintargs.get("fix"):
+        # Do a first pass with --fix-only as the json format doesn't return the
+        # number of fixed issues.
+        output = run_process(config, args + ["--fix-only"])
+        matches = re.match(r"Fixed (\d+) errors?.", output)
+        if matches:
+            fixed = int(matches[1])
+
+    output = run_process(config, args + ["--format=json"])
+    if not output:
+        return []
+
+    try:
+        issues = json.loads(output)
+    except json.JSONDecodeError:
+        log.error(f"could not parse output: {output}")
+        return []
+
+    warning_rules = set(config.get("warning-rules", []))
+    for issue in issues:
+        res = {
+            "path": issue["filename"],
+            "lineno": issue["location"]["row"],
+            "column": issue["location"]["column"],
+            "lineoffset": issue["end_location"]["row"] - issue["location"]["row"],
+            "message": issue["message"],
+            "rule": issue["code"],
+            "level": "warning" if issue["code"] in warning_rules else "error",
+        }
+        if issue["fix"]:
+            res["hint"] = issue["fix"]["message"]
+
+        results.append(result.from_config(config, **res))
+
+    return {"results": results, "fixed": fixed}
diff --git a/tools/lint/python/ruff_requirements.in b/tools/lint/python/ruff_requirements.in
new file mode 100644
index 000000000000..af3ee5763862
--- /dev/null
+++ b/tools/lint/python/ruff_requirements.in
@@ -0,0 +1 @@
+ruff
diff --git a/tools/lint/python/ruff_requirements.txt b/tools/lint/python/ruff_requirements.txt
new file mode 100644
index 000000000000..1c8943c26b69
--- /dev/null
+++ b/tools/lint/python/ruff_requirements.txt
@@ -0,0 +1,25 @@
+#
+# This file is autogenerated by pip-compile with Python 3.7
+# by the following command:
+#
+#    pip-compile --generate-hashes ruff_requirements.in
+#
+ruff==0.0.254 \
+    --hash=sha256:059a380c08e849b6f312479b18cc63bba2808cff749ad71555f61dd930e3c9a2 \
+    --hash=sha256:09c764bc2bd80c974f7ce1f73a46092c286085355a5711126af351b9ae4bea0c \
+    --hash=sha256:0deb1d7226ea9da9b18881736d2d96accfa7f328c67b7410478cc064ad1fa6aa \
+    --hash=sha256:0eb66c9520151d3bd950ea43b3a088618a8e4e10a5014a72687881e6f3606312 \
+    --hash=sha256:27d39d697fdd7df1f2a32c1063756ee269ad8d5345c471ee3ca450636d56e8c6 \
+    --hash=sha256:2fc21d060a3197ac463596a97d9b5db2d429395938b270ded61dd60f0e57eb21 \
+    --hash=sha256:688379050ae05394a6f9f9c8471587fd5dcf22149bd4304a4ede233cc4ef89a1 \
+    --hash=sha256:8deba44fd563361c488dedec90dc330763ee0c01ba54e17df54ef5820079e7e0 \
+    --hash=sha256:ac1429be6d8bd3db0bf5becac3a38bd56f8421447790c50599cd90fd53417ec4 \
+    --hash=sha256:b3f15d5d033fd3dcb85d982d6828ddab94134686fac2c02c13a8822aa03e1321 \
+    --hash=sha256:b435afc4d65591399eaf4b2af86e441a71563a2091c386cadf33eaa11064dc09 \
+    --hash=sha256:c38291bda4c7b40b659e8952167f386e86ec29053ad2f733968ff1d78b4c7e15 \
+    --hash=sha256:d4385cdd30153b7aa1d8f75dfd1ae30d49c918ead7de07e69b7eadf0d5538a1f \
+    --hash=sha256:dd58c500d039fb381af8d861ef456c3e94fd6855c3d267d6c6718c9a9fe07be0 \
+    --hash=sha256:e15742df0f9a3615fbdc1ee9a243467e97e75bf88f86d363eee1ed42cedab1ec \
+    --hash=sha256:ef20bf798ffe634090ad3dc2e8aa6a055f08c448810a2f800ab716cc18b80107 \
+    --hash=sha256:f70dc93bc9db15cccf2ed2a831938919e3e630993eeea6aba5c84bc274237885
+    # via -r ruff_requirements.in
diff --git a/tools/lint/ruff.yml b/tools/lint/ruff.yml
new file mode 100644
index 000000000000..b05c347c0cba
--- /dev/null
+++ b/tools/lint/ruff.yml
@@ -0,0 +1,17 @@
+---
+ruff:
+    description: An extremely fast Python linter, written in Rust
+    # Excludes should be added to topsrcdir/pyproject.toml
+    exclude: []
+    # The configure option is used by the build system
+    extensions: ["configure", "py"]
+    support-files:
+        - "**/.ruff.toml"
+        - "**/ruff.toml"
+        - "**/pyproject.toml"
+        - "tools/lint/python/ruff.py"
+    # Rules that should result in warnings rather than errors.
+    warning-rules: []
+    type: external
+    payload: python.ruff:lint
+    setup: python.ruff:setup
diff --git a/tools/lint/test/files/flake8/.flake8 b/tools/lint/test/files/flake8/.flake8
deleted file mode 100644
index 1933432319ea..000000000000
--- a/tools/lint/test/files/flake8/.flake8
+++ /dev/null
@@ -1,4 +0,0 @@
-[flake8]
-max-line-length = 100
-exclude =
-    subdir/exclude,
diff --git a/tools/lint/test/files/flake8/bad.py b/tools/lint/test/files/flake8/bad.py
deleted file mode 100644
index 9d9751c7eb97..000000000000
--- a/tools/lint/test/files/flake8/bad.py
+++ /dev/null
@@ -1,5 +0,0 @@
-# Unused import
-import distutils
-
-print("This is a line that is over 80 characters but under 100. It shouldn't fail.")
-print("This is a line that is over not only 80, but 100 characters. It should most certainly cause a failure.")
diff --git a/tools/lint/test/files/flake8/custom/.flake8 b/tools/lint/test/files/flake8/custom/.flake8
deleted file mode 100644
index cfe68833f239..000000000000
--- a/tools/lint/test/files/flake8/custom/.flake8
+++ /dev/null
@@ -1,4 +0,0 @@
-[flake8]
-max-line-length=110
-ignore=
-    F401
diff --git a/tools/lint/test/files/flake8/custom/good.py b/tools/lint/test/files/flake8/custom/good.py
deleted file mode 100644
index 7f9121a2ba7a..000000000000
--- a/tools/lint/test/files/flake8/custom/good.py
+++ /dev/null
@@ -1,5 +0,0 @@
-# Unused import
-import distutils
-
-print("This is a line that is over 80 characters but under 100. It shouldn't fail.")
-print("This is a line that is over not only 80, but 100 characters. It should also not cause a failure.")
diff --git a/tools/lint/test/files/flake8/ext/bad.configure b/tools/lint/test/files/flake8/ext/bad.configure
deleted file mode 100644
index 8214ebb3c06d..000000000000
--- a/tools/lint/test/files/flake8/ext/bad.configure
+++ /dev/null
@@ -1,2 +0,0 @@
-# unused import
-import os
diff --git a/tools/lint/test/files/flake8/subdir/exclude/bad.py b/tools/lint/test/files/flake8/subdir/exclude/bad.py
deleted file mode 100644
index 9d9751c7eb97..000000000000
--- a/tools/lint/test/files/flake8/subdir/exclude/bad.py
+++ /dev/null
@@ -1,5 +0,0 @@
-# Unused import
-import distutils
-
-print("This is a line that is over 80 characters but under 100. It shouldn't fail.")
-print("This is a line that is over not only 80, but 100 characters. It should most certainly cause a failure.")
diff --git a/tools/lint/test/files/flake8/subdir/exclude/exclude_subdir/bad.py b/tools/lint/test/files/flake8/subdir/exclude/exclude_subdir/bad.py
deleted file mode 100644
index 9d9751c7eb97..000000000000
--- a/tools/lint/test/files/flake8/subdir/exclude/exclude_subdir/bad.py
+++ /dev/null
@@ -1,5 +0,0 @@
-# Unused import
-import distutils
-
-print("This is a line that is over 80 characters but under 100. It shouldn't fail.")
-print("This is a line that is over not only 80, but 100 characters. It should most certainly cause a failure.")
diff --git a/tools/lint/test/files/ruff/bad.py b/tools/lint/test/files/ruff/bad.py
new file mode 100644
index 000000000000..0015d7e7f9d6
--- /dev/null
+++ b/tools/lint/test/files/ruff/bad.py
@@ -0,0 +1,4 @@
+import distutils
+
+if not "foo" in "foobar":
+    print("oh no!")
diff --git a/tools/lint/test/files/ruff/ruff.toml b/tools/lint/test/files/ruff/ruff.toml
new file mode 100644
index 000000000000..34f5ca74a453
--- /dev/null
+++ b/tools/lint/test/files/ruff/ruff.toml
@@ -0,0 +1 @@
+# Empty config to force ruff to ignore the global one.
diff --git a/tools/lint/test/python.ini b/tools/lint/test/python.ini
index c09db40dccf4..4d181380a180 100644
--- a/tools/lint/test/python.ini
+++ b/tools/lint/test/python.ini
@@ -13,8 +13,6 @@ skip-if = os == "win"  # busts the tree for subsequent tasks on the same worker
 [test_file_perm.py]
 skip-if = os == "win"
 [test_file_whitespace.py]
-[test_flake8.py]
-requirements = tools/lint/python/flake8_requirements.txt
 [test_fluent_lint.py]
 [test_lintpref.py]
 [test_manifest_alpha.py]
@@ -26,6 +24,8 @@ requirements = tools/lint/python/flake8_requirements.txt
 requirements = tools/lint/python/pylint_requirements.txt
 [test_rst.py]
 requirements = tools/lint/rst/requirements.txt
+[test_ruff.py]
+requirements = tools/lint/python/ruff_requirements.txt
 [test_rustfmt.py]
 [test_shellcheck.py]
 [test_trojan_source.py]
diff --git a/tools/lint/test/test_flake8.py b/tools/lint/test/test_flake8.py
deleted file mode 100644
index d44e3828edd2..000000000000
--- a/tools/lint/test/test_flake8.py
+++ /dev/null
@@ -1,117 +0,0 @@
-import os
-
-import mozunit
-
-LINTER = "flake8"
-fixed = 0
-
-
-def test_lint_single_file(lint, paths):
-    results = lint(paths("bad.py"))
-    assert len(results) == 2
-    assert results[0].rule == "F401"
-    assert results[0].level == "error"
-    assert results[1].rule == "E501"
-    assert results[1].level == "error"
-    assert results[1].lineno == 5
-
-    # run lint again to make sure the previous results aren't counted twice
-    results = lint(paths("bad.py"))
-    assert len(results) == 2
-
-
-def test_lint_custom_config_ignored(lint, paths):
-    results = lint(paths("custom"))
-    assert len(results) == 2
-
-    results = lint(paths("custom/good.py"))
-    assert len(results) == 2
-
-
-def test_lint_fix(lint, create_temp_file):
-    global fixed
-    contents = """
-import distutils
-
-def foobar():
-    pass
-""".lstrip()
-
-    path = create_temp_file(contents, name="bad.py")
-    results = lint([path])
-    assert len(results) == 2
-
-    # Make sure the missing blank line is fixed, but the unused import isn't.
-    results = lint([path], fix=True)
-    assert len(results) == 1
-    assert fixed == 1
-
-    fixed = 0
-
-    # Also test with a directory
-    path = os.path.dirname(create_temp_file(contents, name="bad2.py"))
-    results = lint([path], fix=True)
-    # There should now be two files with 2 combined errors
-    assert len(results) == 2
-    assert fixed == 1
-    assert all(r.rule != "E501" for r in results)
-
-
-def test_lint_fix_uses_config(lint, create_temp_file):
-    contents = """
-foo = ['A list of strings', 'that go over 80 characters', 'to test if autopep8 fixes it']
-""".lstrip()
-
-    path = create_temp_file(contents, name="line_length.py")
-    lint([path], fix=True)
-
-    # Make sure autopep8 reads the global config under lintargs['root']. If it
-    # didn't, then the line-length over 80 would get fixed.
-    with open(path, "r") as fh:
-        assert fh.read() == contents
-
-
-def test_lint_excluded_file(lint, paths, config):
-    # First file is globally excluded, second one is from .flake8 config.
-    files = paths("bad.py", "subdir/exclude/bad.py", "subdir/exclude/exclude_subdir")
-    config["exclude"] = paths("bad.py")
-    results = lint(files, config)
-    print(results)
-    assert len(results) == 0
-
-    # Make sure excludes also apply when running from a different cwd.
-    cwd = paths("subdir")[0]
-    os.chdir(cwd)
-
-    results = lint(paths("subdir/exclude"))
-    print(results)
-    assert len(results) == 0
-
-
-def test_lint_excluded_file_with_glob(lint, paths, config):
-    config["exclude"] = paths("ext/*.configure")
-
-    files = paths("ext")
-    results = lint(files, config)
-    print(results)
-    assert len(results) == 0
-
-    files = paths("ext/bad.configure")
-    results = lint(files, config)
-    print(results)
-    assert len(results) == 0
-
-
-def test_lint_excluded_file_with_no_filter(lint, paths, config):
-    results = lint(paths("subdir/exclude"), use_filters=False)
-    print(results)
-    assert len(results) == 4
-
-
-def test_lint_uses_custom_extensions(lint, paths):
-    assert len(lint(paths("ext"))) == 1
-    assert len(lint(paths("ext/bad.configure"))) == 1
-
-
-if __name__ == "__main__":
-    mozunit.main()
diff --git a/tools/lint/test/test_ruff.py b/tools/lint/test/test_ruff.py
new file mode 100644
index 000000000000..fbb483780e54
--- /dev/null
+++ b/tools/lint/test/test_ruff.py
@@ -0,0 +1,39 @@
+# -*- coding: utf-8 -*-
+
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+from pprint import pprint
+from textwrap import dedent
+
+import mozunit
+
+LINTER = "ruff"
+fixed = 0
+
+
+def test_lint_fix(lint, create_temp_file):
+    contents = dedent(
+        """
+    import distutils
+    print("hello!")
+    """
+    )
+
+    path = create_temp_file(contents, "bad.py")
+    lint([path], fix=True)
+    assert fixed == 1
+
+
+def test_lint_ruff(lint, paths):
+    results = lint(paths())
+    pprint(results, indent=2)
+    assert len(results) == 2
+    assert results[0].level == "error"
+    assert results[0].relpath == "bad.py"
+    assert "`distutils` imported but unused" in results[0].message
+
+
+if __name__ == "__main__":
+    mozunit.main()