diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 1b85860..ddb8c0a 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: ["3.14"]
+        python-version: ["3.15"]
         toxenv: [black, ruff, mypy]
     steps:
     - uses: actions/checkout@v7
@@ -34,28 +34,28 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest]
-        python-version: ["3.11", "3.12", "3.13", "3.14", "3.14t"]
+        python-version: ["3.11", "3.12", "3.13", "3.14", "3.14t", "3.15", "3.15t"]
         optional-deps: [true]
         with-libs: [true]
         include:
         - os: macos-latest
-          python-version: "3.14"
+          python-version: "3.15"
           optional-deps: true
         - os: ubuntu-latest
-          python-version: "3.14"
+          python-version: "3.15"
           with-libs: false
           optional-deps: false
         - os: ubuntu-latest
-          python-version: "3.14"
+          python-version: "3.15"
           with-libs: false
           optional-deps: true
         - os: ubuntu-latest
-          python-version: "3.14"
+          python-version: "3.15"
           optional-deps: false
           with-libs: false
           with-zstandard: true
         - os: windows-latest
-          python-version: "3.14"
+          python-version: "3.15"
     steps:
     - name: Install optional tools macOS
       if: runner.os == 'macOS' && matrix.optional-deps
@@ -85,7 +85,7 @@ jobs:
       if: matrix.with-zstandard
       run: tox run -e zstd
     - name: Test with LZ4 bindings
-      if: matrix.os == 'ubuntu-latest' && matrix.python-version == '3.14' && matrix.optional-deps && matrix.with-libs
+      if: matrix.os == 'ubuntu-latest' && matrix.python-version == '3.15' && matrix.optional-deps && matrix.with-libs
       run: tox run -e lz4
     - name: Upload coverage report
       uses: codecov/codecov-action@v7
@@ -102,7 +102,7 @@ jobs:
     - name: Set up Python
       uses: actions/setup-python@v7
       with:
-        python-version: "3.14"
+        python-version: "3.15"
     - name: Make distributions
       run: |
         python -m pip install build
diff --git a/README.rst b/README.rst
index b854367..88c330e 100644
--- a/README.rst
+++ b/README.rst
@@ -195,6 +195,7 @@ development version
 * PipedCompressionReader no longer has seek/tell methods. This only worked
   on Windows before (and only sometimes).
 * Dropped support for Python 3.10
+* Started supporting Python 3.15
 
 v2.1.0 (2026-06-03)
 ~~~~~~~~~~~~~~~~~~~
diff --git a/tox.toml b/tox.toml
index 7f7af1f..11c6b79 100644
--- a/tox.toml
+++ b/tox.toml
@@ -1,7 +1,7 @@
-env_list = ["black", "ruff", "mypy", "3.11", "3.12", "3.13", "3.14", "3.14t"]
+env_list = ["black", "ruff", "mypy", "3.11", "3.12", "3.13", "3.14", "3.14t", "3.15", "3.15t"]
 
 [env_run_base]
-default_base_python = "3.14"
+default_base_python = "3.15"
 deps = [
     "pytest",
     "pytest-timeout",
@@ -32,7 +32,7 @@ commands = [
 ]
 
 [env.black]
-base_python = "3.14"
+base_python = "3.15"
 deps = ["black==26.10"]
 skip_install = true
 commands = [["black", "--check", "src/", "tests/"]]