By default it seems once you’ve installed Steam on macOS, it automatically starts running on startup. I feel like this is really annoying, since playing a game isn’t always the first thing I want to do when I startup my machine.
How to stop Steam from running at startup on macOS
With Steam open:
- Click on Steam
- Select Preferences…
- Click on the Interface tab
- Uncheck the box that says Run Steam when my computer starts
Now every time your macOS machine starts up, Steam shouldn’t run until you open it.