Should I deploy Windows Server 2025 domain controllers alongside 2019 and 2022 servers?

Keeping the domain controllers on Windows Server 2022 is also a reasonable choice if you want a lower-risk transition. Server 2022 will remain supported for quite a while, and you can use the new hardware with a 2022 VM now, then introduce 2025 after testing. Just make sure the VM has reliable storage, time synchronization is configured correctly, and you never rely on a single virtual domain controller.

The bigger question is whether your environment still depends on legacy authentication. Windows Server 2025 has stronger security defaults and continued movement away from older protocols such as NTLM. It may work normally, but old applications, scripts, or devices that rely on legacy authentication can expose problems. Inventory those dependencies and test them before making the new controller authoritative.

You can add a Windows Server 2025 domain controller to an existing domain with 2019 and 2022 servers, then transfer the FSMO roles and demote the older controller when you're ready. Mixed-version environments are generally supported, so you don't need to upgrade every server at once. Make sure the new system is fully patched and verify replication, DNS, authentication, and backups before retiring anything.

We had a mixed environment containing Server 2016, 2019, and 2025 domain controllers during a staged migration and it worked without major issues. We added the new controllers, confirmed replication at each site, moved the FSMO roles, and then demoted the older systems. That said, compatibility depends heavily on the applications and policies in your environment, so test before deploying broadly.