diff --git a/.github/config/macos-pkg-choices-freethreaded-3.15t.xml b/.github/config/macos-pkg-choices-freethreaded-3.15t.xml
new file mode 100644
index 00000000..271377a8
--- /dev/null
+++ b/.github/config/macos-pkg-choices-freethreaded-3.15t.xml
@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<array>
+    <dict>
+        <key>attributeSetting</key>
+        <integer>1</integer>
+        <key>choiceAttribute</key>
+        <string>selected</string>
+        <key>choiceIdentifier</key>
+        <string>org.python.Python.PythonTFramework-3.15</string>
+    </dict>
+</array>
+</plist>
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index e40d10de..9bf402c5 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -19,6 +19,8 @@ jobs:
           - {VERSION: "3.9", NOXSESSION: "tests"}
           - {VERSION: "3.14", NOXSESSION: "tests"}
           - {VERSION: "3.14t", NOXSESSION: "tests"}
+          - {VERSION: "3.15", NOXSESSION: "tests"}
+          - {VERSION: "3.15t", NOXSESSION: "tests"}
         MACOS:
           - macos-15-intel
           - macos-latest
@@ -32,6 +34,7 @@ jobs:
         uses: actions/setup-python@5fda3b95a4ea91299a34e894583c3862153e4b97 # v7.0.0
         with:
           python-version: ${{ matrix.PYTHON.VERSION }}
+          allow-prereleases: true
       - uses: actions/cache@55cc8345863c7cc4c66a329aec7e433d2d1c52a9 # v6.1.0
         timeout-minutes: 5
         with:
@@ -57,6 +60,8 @@ jobs:
           - {VERSION: "3.9", NOXSESSION: "tests"}
           - {VERSION: "3.14", NOXSESSION: "tests"}
           - {VERSION: "3.14t", NOXSESSION: "tests"}
+          - {VERSION: "3.15", NOXSESSION: "tests"}
+          - {VERSION: "3.15t", NOXSESSION: "tests"}
     name: "Python ${{ matrix.PYTHON.VERSION }} on ${{ matrix.WINDOWS.WINDOWS }}"
     steps:
       - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
@@ -67,6 +72,7 @@ jobs:
         uses: actions/setup-python@5fda3b95a4ea91299a34e894583c3862153e4b97 # v7.0.0
         with:
           python-version: ${{ matrix.PYTHON.VERSION }}
+          allow-prereleases: true
           architecture: ${{ matrix.WINDOWS.ARCH }}
       - uses: actions/cache@55cc8345863c7cc4c66a329aec7e433d2d1c52a9 # v6.1.0
         timeout-minutes: 5
@@ -96,6 +102,8 @@ jobs:
           - {VERSION: "3.13", NOXSESSION: "tests"}
           - {VERSION: "3.14", NOXSESSION: "tests"}
           - {VERSION: "3.14t", NOXSESSION: "tests"}
+          - {VERSION: "3.15", NOXSESSION: "tests"}
+          - {VERSION: "3.15t", NOXSESSION: "tests"}
           - {VERSION: "pypy-3.11", NOXSESSION: "tests"}
 
           # MSRV
@@ -112,6 +120,7 @@ jobs:
         uses: actions/setup-python@5fda3b95a4ea91299a34e894583c3862153e4b97 # v7.0.0
         with:
           python-version: ${{ matrix.PYTHON.VERSION }}
+          allow-prereleases: true
       - uses: actions/cache@55cc8345863c7cc4c66a329aec7e433d2d1c52a9 # v6.1.0
         timeout-minutes: 5
         with:
diff --git a/.github/workflows/wheel-builder.yml b/.github/workflows/wheel-builder.yml
index 4bdbdc91..e4ce0f5c 100644
--- a/.github/workflows/wheel-builder.yml
+++ b/.github/workflows/wheel-builder.yml
@@ -50,6 +50,7 @@ jobs:
           - { VERSION: "cp39-cp39", ABI_VERSION: 'cp39' }
           - { VERSION: "pp311-pypy311_pp73" }
           - { VERSION: "cp314-cp314t" }
+          - { VERSION: "cp315-cp315t" }
         MANYLINUX:
           - { NAME: "manylinux2014_x86_64", CONTAINER: "cryptography-manylinux2014:x86_64", RUNNER: "ubuntu-latest" }
           - { NAME: "manylinux_2_28_x86_64", CONTAINER: "cryptography-manylinux_2_28:x86_64", RUNNER: "ubuntu-latest"}
@@ -138,6 +139,9 @@ jobs:
           - VERSION: '3.14t'
             DOWNLOAD_URL: 'https://www.python.org/ftp/python/3.14.0/python-3.14.0-macos11.pkg'
             BIN_PATH: '/Library/Frameworks/PythonT.framework/Versions/3.14/bin/python3.14t'
+          - VERSION: '3.15t'
+            DOWNLOAD_URL: 'https://www.python.org/ftp/python/3.15.0/python-3.15.0-macos11.pkg'
+            BIN_PATH: '/Library/Frameworks/PythonT.framework/Versions/3.15/bin/python3.15t'
     name: "Python ${{ matrix.PYTHON.VERSION }} ${{ matrix.PYTHON.ABI_VERSION }} on macOS"
     steps:
       - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
@@ -146,6 +150,7 @@ jobs:
           ref: ${{ github.event.inputs.version || github.ref }}
           sparse-checkout: |
             .github/config/macos-pkg-choices-freethreaded-3.14t.xml
+            .github/config/macos-pkg-choices-freethreaded-3.15t.xml
           persist-credentials: false
       - name: Install Python
         if: ${{ !endsWith(matrix.PYTHON.VERSION, 't') }}
@@ -203,6 +208,7 @@ jobs:
         PYTHON:
           - {VERSION: "3.11", ABI_VERSION: "cp39"}
           - {VERSION: "3.14t"}
+          - {VERSION: "3.15t"}
     name: "${{ matrix.PYTHON.VERSION }} ${{ matrix.PYTHON.ABI_VERSION }} ${{ matrix.WINDOWS.ARCH }}"
     steps:
       - uses: actions/download-artifact@3e5f45b2cfb9172054b4087a40e8e0b5a5461e7c # v8.0.1
@@ -212,6 +218,7 @@ jobs:
         uses: actions/setup-python@5fda3b95a4ea91299a34e894583c3862153e4b97 # v7.0.0
         with:
           python-version: ${{ matrix.PYTHON.VERSION }}
+          allow-prereleases: true
           architecture: ${{ matrix.WINDOWS.ARCH }}
       - uses: dtolnay/rust-toolchain@e2a55d2ffb04f378e9626c28d38b36d230d1e12f
         with:
diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index 3a790dbb..524eeb74 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -8,6 +8,8 @@ Unreleased
 * Dropped support for Python 3.8.
 * Dropped support for free-threaded Python 3.13 (free-threaded Python 3.14 is
   still supported).
+* Added support for Python 3.15 and free-threaded Python 3.15.
+* We now publish wheels for free-threaded Python 3.15.
 
 5.0.0
 -----
diff --git a/pyproject.toml b/pyproject.toml
index ebfc29fc..9747a635 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -28,6 +28,7 @@ classifiers = [
     "Programming Language :: Python :: 3.12",
     "Programming Language :: Python :: 3.13",
     "Programming Language :: Python :: 3.14",
+    "Programming Language :: Python :: 3.15",
     "Programming Language :: Python :: Free Threading :: 3 - Stable",
 ]
 requires-python = ">= 3.9"