diff --git a/.circleci/config.yml b/.circleci/config.yml
index 40ba933cf0d9..94090783b764 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -103,10 +103,10 @@ commands:
       - run:
           name: Install Python dependencies
           command: |
-            python -m pip install --user -r requirements/dev/build-requirements.txt
+            python -m pip install --user --group build
             python -m pip install --user \
                 numpy<< parameters.numpy_version >> \
-                -r requirements/doc/doc-requirements.txt
+                --group doc
             python -m pip install --no-deps --user \
                 git+https://github.com/matplotlib/mpl-sphinx-theme.git
 
diff --git a/.github/workflows/cygwin.yml b/.github/workflows/cygwin.yml
index 4a5b79c0538e..e807dd85288f 100644
--- a/.github/workflows/cygwin.yml
+++ b/.github/workflows/cygwin.yml
@@ -143,7 +143,7 @@ jobs:
         uses: actions/cache@5a3ec84eff668545956fd18022155c47e93e2684  # v4.2.3
         with:
           path: C:\cygwin\home\runneradmin\.cache\pip
-          key: Cygwin-py3.${{ matrix.python-minor-version }}-pip-${{ hashFiles('requirements/*/*.txt') }}
+          key: Cygwin-py3.${{ matrix.python-minor-version }}-pip-${{ hashFiles('pyproject.toml') }}
           restore-keys: ${{ matrix.os }}-py3.${{ matrix.python-minor-version }}-pip-
 
       - name: Cache ccache
@@ -174,15 +174,13 @@ jobs:
       - name: Install Python dependencies
         shell: bash.exe -eo pipefail -o igncr "{0}"
         run: |
-          python -m pip install --upgrade pip setuptools wheel
+          python -m pip install --group build
           python -m pip install kiwisolver 'numpy>=1.22,<1.26' pillow importlib_resources
-          grep -v -F -e psutil requirements/testing/all.txt >requirements_test.txt
-          python -m pip install meson-python pybind11
           export PATH="/usr/local/bin:$PATH"
           python -m pip install --no-build-isolation 'contourpy>=1.0.1'
           python -m pip install --upgrade cycler fonttools \
               packaging pyparsing python-dateutil setuptools-scm \
-              -r requirements_test.txt sphinx ipython
+              --group test sphinx ipython
           python -m pip install --upgrade pycairo 'cairocffi>=0.8' PyGObject &&
              python -c 'import gi; gi.require_version("Gtk", "3.0"); from gi.repository import Gtk' &&
              echo 'PyGObject is available' ||
diff --git a/.github/workflows/reviewdog.yml b/.github/workflows/reviewdog.yml
index c803fcc6ba38..acbc0e26fa26 100644
--- a/.github/workflows/reviewdog.yml
+++ b/.github/workflows/reviewdog.yml
@@ -51,7 +51,7 @@ jobs:
           python-version: '3.11'
 
       - name: Install mypy
-        run: pip3 install -r requirements/testing/mypy.txt -r requirements/testing/all.txt
+        run: pip3 install --group typing
 
       - name: Set up reviewdog
         uses: reviewdog/action-setup@e04ffabe3898a0af8d0fb1af00c188831c4b5893  # v1.3.9
diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 911fa69ec38b..ac42f7a88907 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -50,12 +50,12 @@ jobs:
           - name-suffix: "(Minimum Versions)"
             os: ubuntu-22.04
             python-version: '3.11'
-            extra-requirements: '-c requirements/testing/minver.txt'
+            extra-requirements: 'python -m pip install --upgrade $PRE --group test-minver'
             delete-font-cache: true
           - os: ubuntu-22.04
             python-version: '3.11'
             CFLAGS: "-fno-lto"  # Ensure that disabling LTO works.
-            extra-requirements: '-r requirements/testing/extra.txt'
+            extra-requirements: 'python -m pip install --upgrade $PRE --prefer-binary --group test-extra'
           - os: ubuntu-22.04-arm
             python-version: '3.12'
           - os: ubuntu-22.04
@@ -170,7 +170,7 @@ jobs:
         if: startsWith(runner.os, 'Linux')
         with:
           path: ~/.cache/pip
-          key: ${{ matrix.os }}-py${{ matrix.python-version }}-pip-${{ hashFiles('requirements/*/*.txt') }}
+          key: ${{ matrix.os }}-py${{ matrix.python-version }}-pip-${{ hashFiles('pyproject.toml') }}
           restore-keys: |
             ${{ matrix.os }}-py${{ matrix.python-version }}-pip-
       - name: Cache pip
@@ -178,7 +178,7 @@ jobs:
         if: startsWith(runner.os, 'macOS')
         with:
           path: ~/Library/Caches/pip
-          key: ${{ matrix.os }}-py${{ matrix.python-version }}-pip-${{ hashFiles('requirements/*/*.txt') }}
+          key: ${{ matrix.os }}-py${{ matrix.python-version }}-pip-${{ hashFiles('pyproject.toml') }}
           restore-keys: |
             ${{ matrix.os }}-py${{ matrix.python-version }}-pip-
       - name: Cache ccache
@@ -215,12 +215,8 @@ jobs:
 
           # Install dependencies from PyPI.
           # Preinstall build requirements to enable no-build-isolation builds.
-          python -m pip install --upgrade $PRE \
-            'contourpy>=1.0.1' cycler fonttools kiwisolver importlib_resources \
-            packaging pillow 'pyparsing!=3.1.0' python-dateutil setuptools-scm \
-            'meson-python>=0.13.1' 'pybind11>=2.13.2' \
-            -r requirements/testing/all.txt \
-            ${{ matrix.extra-requirements }}
+          python -m pip install --upgrade $PRE --group build --group test
+          ${{ matrix.extra-requirements }}
 
           # Install optional dependencies from PyPI.
           # Sphinx is needed to run sphinxext tests
diff --git a/azure-pipelines.yml b/azure-pipelines.yml
index cc0fbce11377..df9aa7a2b60c 100644
--- a/azure-pipelines.yml
+++ b/azure-pipelines.yml
@@ -74,8 +74,9 @@ stages:
 
           - bash: |
               python -m pip install --upgrade pip
-              python -m pip install --upgrade -r requirements/dev/build-requirements.txt
-              python -m pip install -r requirements/testing/all.txt -r requirements/testing/extra.txt
+              python -m pip install --upgrade --group build
+              python -m pip install --group test
+              python -m pip install --prefer-binary --group test-extra
             displayName: 'Install dependencies with pip'
 
           - bash: |
diff --git a/doc/devel/development_setup.rst b/doc/devel/development_setup.rst
index 45b95e48e7ff..92fd8d622fac 100644
--- a/doc/devel/development_setup.rst
+++ b/doc/devel/development_setup.rst
@@ -177,7 +177,7 @@ setup.
 
       Install the Python dependencies with ::
 
-        pip install -r requirements/dev/dev-requirements.txt
+        pip install --group dev
 
       Remember to activate the environment whenever you start working on Matplotlib!
 
diff --git a/doc/devel/release_guide.rst b/doc/devel/release_guide.rst
index 0e0ebb98fd1d..460ac194bb4e 100644
--- a/doc/devel/release_guide.rst
+++ b/doc/devel/release_guide.rst
@@ -420,7 +420,7 @@ To build the documentation you must have the tagged version installed, but
 build the docs from the ``ver-doc`` branch.  An easy way to arrange this is::
 
   pip install matplotlib
-  pip install -r requirements/doc/doc-requirements.txt
+  pip install --group doc
   git checkout v3.7.0-doc
   git clean -xfd
   make -Cdoc O="-t release -j$(nproc)" html latexpdf LATEXMKOPTS="-silent -f"
diff --git a/doc/install/dependencies.rst b/doc/install/dependencies.rst
index 2a68672a3be0..0bd268e48931 100644
--- a/doc/install/dependencies.rst
+++ b/doc/install/dependencies.rst
@@ -396,17 +396,11 @@ Documentation dependencies
 Python
 ------
 
-The additional Python packages required to build the
-:ref:`documentation <documenting-matplotlib>` are listed in
-:file:`doc-requirements.txt` and can be installed using ::
-
-    pip install -r requirements/doc/doc-requirements.txt
-
-The content of :file:`doc-requirements.txt` is also shown below:
-
-.. include:: ../../requirements/doc/doc-requirements.txt
-   :literal:
+The additional Python packages required to build the :ref:`documentation
+<documenting-matplotlib>` are listed in :file:`pyproject.toml` and can be
+installed using ::
 
+    pip install --group doc
 
 .. _doc-dependencies-external:
 
diff --git a/pyproject.toml b/pyproject.toml
index 84e0b774f06c..c2a996deb2fb 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -24,10 +24,9 @@ classifiers=[
 
 # When updating the list of dependencies, add an api_changes/development
 # entry and also update the following places:
+# - the `build` and `test-minver` dependency groups below
 # - lib/matplotlib/__init__.py (matplotlib._check_versions())
-# - requirements/testing/minver.txt
 # - doc/devel/dependencies.rst
-# - .github/workflows/tests.yml
 # - environment.yml
 dependencies = [
     "contourpy >= 1.0.1",
@@ -42,20 +41,6 @@ dependencies = [
 ]
 requires-python = ">=3.11"
 
-[project.optional-dependencies]
-# Should be a copy of the build dependencies below.
-dev = [
-    "meson-python>=0.13.1,<0.17.0",
-    "pybind11>=2.13.2,!=2.13.3",
-    "setuptools_scm>=7",
-    # Not required by us but setuptools_scm without a version, cso _if_
-    # installed, then setuptools_scm 8 requires at least this version.
-    # Unfortunately, we can't do a sort of minimum-if-installed dependency, so
-    # we need to keep this for now until setuptools_scm _fully_ drops
-    # setuptools.
-    "setuptools>=64",
-]
-
 [project.urls]
 "Homepage" = "https://matplotlib.org"
 "Download" = "https://matplotlib.org/stable/install/index.html"
@@ -67,13 +52,137 @@ dev = [
 
 [build-system]
 build-backend = "mesonpy"
-# Also keep in sync with optional dependencies above.
+# Also keep in sync with dependency groups below.
 requires = [
     "meson-python>=0.13.1,<0.17.0",
     "pybind11>=2.13.2,!=2.13.3",
     "setuptools_scm>=7",
 ]
 
+[dependency-groups]
+build = [
+    # Should be the same as `[project] dependencies` above.
+    "contourpy >= 1.0.1",
+    "cycler >= 0.10",
+    "fonttools >= 4.22.0",
+    "kiwisolver >= 1.3.1",
+    "numpy >= 1.25",
+    "packaging >= 20.0",
+    "pillow >= 9",
+    "pyparsing >= 3",
+    "python-dateutil >= 2.7",
+
+    # Should be the same as `[build-system] requires` above.
+    "meson-python>=0.13.1,<0.17.0",
+    "pybind11>=2.13.2,!=2.13.3",
+    "setuptools_scm>=7",
+    # Not required by us but setuptools_scm without a version, so _if_
+    # installed, then setuptools_scm 8 requires at least this version.
+    # Unfortunately, we can't do a sort of minimum-if-installed dependency, so
+    # we need to keep this for now until setuptools_scm _fully_ drops
+    # setuptools.
+    "setuptools>=64",
+]
+dev = [
+    {include-group = "build"},
+    {include-group = "doc"},
+    {include-group = "test"},
+    {include-group = "test-extra"},
+    "ruff",
+]
+# Requirements for building docs
+#
+# You will first need a matching Matplotlib installation
+# e.g (from the Matplotlib root directory)
+#     pip install --group build --no-build-isolation --editable .
+#
+# Install the documentation requirements with:
+#     pip install --group doc
+#
+doc = [
+    "sphinx>=5.1.0,!=6.1.2",
+    "colorspacious",
+    "ipython",
+    "ipywidgets",
+    "ipykernel",
+    "numpydoc>=1.0",
+    "pydata-sphinx-theme~=0.15.0",
+    "mpl-sphinx-theme~=3.9.0",
+    "pyyaml",
+    "PyStemmer",
+    "sphinxcontrib-svg2pdfconverter>=1.1.0",
+    "sphinxcontrib-video>=0.2.1",
+    "sphinx-copybutton",
+    "sphinx-design",
+    "sphinx-gallery[parallel]>=0.12.0",
+    "sphinx-tags>=0.4.0",
+]
+
+# pip requirements for all the CI builds
+test = [
+    "black<24",
+    "certifi",
+    "coverage!=6.3",
+    "psutil; sys_platform != 'cygwin'",
+    "pytest!=4.6.0,!=5.4.0,!=8.1.0",
+    "pytest-cov",
+    "pytest-rerunfailures",
+    "pytest-timeout",
+    "pytest-xdist",
+    "pytest-xvfb",
+    "tornado",
+]
+
+# Extra pip requirements
+test-extra = [
+    "ipykernel",
+    # jupyter/nbconvert#1970 for the 7.3 series exclusions
+    "nbconvert[execute]!=6.0.0,!=6.0.1,!=7.3.0,!=7.3.1",
+    "nbformat!=5.0.0,!=5.0.1",
+    "pandas!=0.25.0",
+    "pikepdf",
+    "pytz",
+    "pywin32; sys_platform == 'win32'",
+    "xarray",
+]
+
+# Extra pip requirements for the minimum-version CI run
+test-minver = [
+    "contourpy==1.0.1",
+    "cycler==0.10",
+    "fonttools==4.22.0",
+    "importlib-resources==3.2.0",
+    "kiwisolver==1.3.2",
+    "meson-python==0.13.1",
+    "meson==1.1.0",
+    "numpy==1.25.0",
+    "packaging==20.0",
+    "pillow==9.0.1",
+    "pyparsing==3.0.0",
+    "pytest==7.0.0",
+    "python-dateutil==2.7",
+    # Test ipython/matplotlib-inline before backend mapping moved to mpl.
+    # This should be tested for a reasonably long transition period,
+    # but we will eventually remove the test when we no longer support
+    # ipython/matplotlib-inline versions from before the transition.
+    "ipython==7.29.0",
+    "ipykernel==5.5.6",
+    "matplotlib-inline<0.1.7",
+]
+
+# Extra pip requirements for the GitHub Actions mypy build
+typing = [
+    "mypy>=1.9",
+    "typing-extensions>=4.6",
+    # Extra stubs distributed separately from the main pypi package
+    "pandas-stubs",
+    "types-pillow",
+    "types-python-dateutil",
+    "types-psutil",
+    "sphinx",
+    {include-group = "build"},
+]
+
 [tool.meson-python.args]
 install = ['--tags=data,python-runtime,runtime']
 
diff --git a/requirements/dev/build-requirements.txt b/requirements/dev/build-requirements.txt
deleted file mode 100644
index 4d2a098c3c4f..000000000000
--- a/requirements/dev/build-requirements.txt
+++ /dev/null
@@ -1,3 +0,0 @@
-pybind11>=2.13.2,!=2.13.3
-meson-python
-setuptools-scm
diff --git a/requirements/dev/dev-requirements.txt b/requirements/dev/dev-requirements.txt
deleted file mode 100644
index 3208949ba0e8..000000000000
--- a/requirements/dev/dev-requirements.txt
+++ /dev/null
@@ -1,5 +0,0 @@
--r build-requirements.txt
--r ../doc/doc-requirements.txt
--r ../testing/all.txt
--r ../testing/extra.txt
-ruff
diff --git a/requirements/doc/doc-requirements.txt b/requirements/doc/doc-requirements.txt
deleted file mode 100644
index 77cb606130b0..000000000000
--- a/requirements/doc/doc-requirements.txt
+++ /dev/null
@@ -1,26 +0,0 @@
-# Requirements for building docs
-#
-# You will first need a matching Matplotlib installation
-# e.g (from the Matplotlib root directory)
-#     pip install --no-build-isolation --editable .[dev]
-#
-# Install the documentation requirements with:
-#     pip install -r requirements/doc/doc-requirements.txt
-#
-sphinx>=5.1.0,!=6.1.2
-colorspacious
-ipython
-ipywidgets
-ipykernel
-numpydoc>=1.0
-packaging>=20
-pydata-sphinx-theme~=0.15.0
-mpl-sphinx-theme~=3.9.0
-pyyaml
-PyStemmer
-sphinxcontrib-svg2pdfconverter>=1.1.0
-sphinxcontrib-video>=0.2.1
-sphinx-copybutton
-sphinx-design
-sphinx-gallery[parallel]>=0.12.0
-sphinx-tags>=0.4.0
diff --git a/requirements/testing/all.txt b/requirements/testing/all.txt
deleted file mode 100644
index e386924a9b67..000000000000
--- a/requirements/testing/all.txt
+++ /dev/null
@@ -1,13 +0,0 @@
-# pip requirements for all the CI builds
-
-black<24
-certifi
-coverage!=6.3
-psutil
-pytest!=4.6.0,!=5.4.0,!=8.1.0
-pytest-cov
-pytest-rerunfailures
-pytest-timeout
-pytest-xdist
-pytest-xvfb
-tornado
diff --git a/requirements/testing/extra.txt b/requirements/testing/extra.txt
deleted file mode 100644
index e0d84d71c781..000000000000
--- a/requirements/testing/extra.txt
+++ /dev/null
@@ -1,12 +0,0 @@
-# Extra pip requirements
-
---prefer-binary
-ipykernel
-# jupyter/nbconvert#1970 for the 7.3 series exclusions
-nbconvert[execute]!=6.0.0,!=6.0.1,!=7.3.0,!=7.3.1
-nbformat!=5.0.0,!=5.0.1
-pandas!=0.25.0
-pikepdf
-pytz
-pywin32; sys.platform == 'win32'
-xarray
diff --git a/requirements/testing/minver.txt b/requirements/testing/minver.txt
deleted file mode 100644
index ee55f6c7b1bf..000000000000
--- a/requirements/testing/minver.txt
+++ /dev/null
@@ -1,23 +0,0 @@
-# Extra pip requirements for the minimum-version CI run
-
-contourpy==1.0.1
-cycler==0.10
-fonttools==4.22.0
-importlib-resources==3.2.0
-kiwisolver==1.3.2
-meson-python==0.13.1
-meson==1.1.0
-numpy==1.25.0
-packaging==20.0
-pillow==9.0.1
-pyparsing==3.0.0
-pytest==7.0.0
-python-dateutil==2.7
-
-# Test ipython/matplotlib-inline before backend mapping moved to mpl.
-# This should be tested for a reasonably long transition period,
-# but we will eventually remove the test when we no longer support
-# ipython/matplotlib-inline versions from before the transition.
-ipython==7.29.0
-ipykernel==5.5.6
-matplotlib-inline<0.1.7
diff --git a/requirements/testing/mypy.txt b/requirements/testing/mypy.txt
deleted file mode 100644
index 343517263f40..000000000000
--- a/requirements/testing/mypy.txt
+++ /dev/null
@@ -1,26 +0,0 @@
-# Extra pip requirements for the GitHub Actions mypy build
-
-mypy>=1.9
-typing-extensions>=4.6
-
-# Extra stubs distributed separately from the main pypi package
-pandas-stubs
-types-pillow
-types-python-dateutil
-types-psutil
-
-sphinx
-
-# Default requirements, included here because mpl itself does not
-# need to be installed for mypy to run, but deps are needed
-# and pip has no --deps-only install command
-contourpy>=1.0.1
-cycler>=0.10
-fonttools>=4.22.0
-kiwisolver>=1.3.1
-packaging>=20.0
-pillow>=9
-pyparsing>=3
-python-dateutil>=2.7
-setuptools_scm>=7
-setuptools>=64
diff --git a/tox.ini b/tox.ini
index 1d527a19ff52..d002a60432f6 100644
--- a/tox.ini
+++ b/tox.ini
@@ -33,6 +33,6 @@ changedir = {tox_root}
 commands =
     python tools/stubtest.py
 usedevelop = False
-deps =
-    -r requirements/testing/mypy.txt
-    -r requirements/testing/all.txt
+dependency_groups =
+    test
+    typing