Gamers with older Macs who want to keep using Steam will need to upgrade to macOS Monterey or later if they can, as Valve is cutting support for macOS Big Sur in October.

Steam will stop supporting macOS 11 Big Sur on October 15, 2025, according to Valve, requiring Mac users to upgrade to macOS ...

Valve's Steam client will end support for macOS 11 Big Sur on October 15, 2025. This decision, while a blow to some gamers, ...

Starting October 15, 2025, Steam will no longer run on macOS 11 Big Sur. Users must upgrade to macOS 12 or later to continue ...

The change kicks in on October 15th, 2025. “This change is required as core features in Steam rely on an embedded version of Google Chrome, which no longer functions on older versions of macOS,” Valve ...