diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index f907026f..26394d4c 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -16,7 +16,7 @@ jobs:
     strategy:
       matrix:
         platform: [ubuntu-latest, windows-latest]
-        python-version: ["3.11", "3.12", "3.13", "3.14"]
+        python-version: ["3.11", "3.12", "3.13", "3.14", "3.15"]
 
     steps:
     - uses: actions/checkout@v4
diff --git a/CHANGES.rst b/CHANGES.rst
index 63a9114f..bc5bb61f 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -5,6 +5,7 @@ Unreleased
 ----------
 
 - **Breaking change**: Drop support for Python 3.10.
+- Add support for Python 3.15.
 - Correct COSE signing header annotations to accept dictionaries and ResolvedHeader in strict type checkers.
 - Annotate factory class methods (``COSE.new``, ``CWT.new``, ``Claims.new``, ``Claims.from_json``, ``Signer.new``, ``Signer.from_jwk``, ``Signer.from_pem``, ``COSEMessage.loads``, etc.) to return ``Self`` for strict type checkers.
 - Modernize type annotations to PEP 604/585 syntax (e.g. ``X | None``, ``dict[str, Any]``) and add pyupgrade (``--py311-plus``) to pre-commit.
diff --git a/tox.ini b/tox.ini
index 3aee9993..c29419c6 100644
--- a/tox.ini
+++ b/tox.ini
@@ -3,7 +3,7 @@ envlist =
     check
     build
     build_docs
-    py{311,312,313,314}
+    py{311,312,313,314,315}
 isolated_build = True
 skip_missing_interpreters = True
 
@@ -14,6 +14,7 @@ python =
     3.12: check, build, build_docs, py312
     3.13: py313
     3.14: py314
+    3.15: py315
 
 
 [testenv:check]