Azure Automation Hybrid Runbook Worker Supported OS

I would separate two things here: what may technically install, and what Microsoft currently documents as supported for production.

For production Hybrid Runbook Workers, I would stay on the documented supported OS list until Microsoft Learn explicitly adds Windows Server 2025 or support confirms it for your tenant/scenario. The safer modernization path is to use extension-based Hybrid Runbook Workers, because agent-based User Hybrid Runbook Workers have been retired.

If you need to move early, I would test Server 2025 in a non-prod worker group with representative runbooks, module versions, managed identity auth, outbound firewall rules, and reboot behavior. But for a supportable production design, keep at least one Windows Server 2022 worker group until the docs catch up.

Relevant docs: https://learn.microsoft.com/azure/automation/extension-based-hybrid-runbook-worker-install and https://learn.microsoft.com/azure/automation/migrate-existing-agent-based-hybrid-worker-to-extension-based-workers