Steam on Mac sometimes gets stuck after a broken download. The result is gigabytes of corrupted install data that Steam cannot clean up on its own.
Short answer: clear the download cache from Steam's Downloads settings, then manually remove any orphaned game folders under ~/Library/Application Support/Steam/steamapps/common.
The built-in cache clear
- open Steam
- click Steam > Settings (or Preferences)
- open Downloads in the sidebar
- click Clear Download Cache
- confirm and log back in
This does not touch installed games or save files. It only removes the temporary install state.
Cleaning orphaned game folders
If a game was uninstalled but still shows up as a folder on disk:
- open Finder
- press Command + Shift + G
- paste
~/Library/Application Support/Steam/steamapps/common/and press Enter - drag any folder for a game you uninstalled months ago into the Trash
- empty the Trash
Only remove folders for games you have confirmed as uninstalled in the Steam library. Removing an active game's folder will force a full redownload.
Better next routes
If the drive is still full after Steam is tidy, continue with How to Find Large Hidden Files on Mac.
For broader Mac cleanup, use What Is Purgeable Storage on Mac?.