Python 3.15 Now Supported in GitHub Actions
The actions/python-versions repository has been updated to include Python 3.15, allowing developers to add "3.15" to their GitHub Actions testing matrix.
The actions/python-versions repository on GitHub now contains a reference to the newly released Python 3.15.0. The commit, identified by hash 49858b91c92d27403416ee43117032e91d00ce24, officially adds the version to the list of supported runtimes.
This update means that CI pipelines can now specify "3.15" in a GitHub Actions matrix, running tests against the latest Python interpreter without needing custom setup steps. The change follows a community request that even involved prompting ChatGPT to monitor the repository for the stable release.
Developers can clone the repository and pull updates hourly to stay current, but the new tag eliminates the need for manual polling. The addition aligns with the official Python 3.15.0 release page, providing a seamless integration path for projects targeting the newest language features.
For more details, see Simon Willison’s post on October 10, 2026, which links directly to the commit and discusses the practical impact on CI workflows.
*Source: Simon Willison*
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