The short answer
Usually, after a check. Might hold something you care about. Look inside before removing it.
What is it?
Unity Hub installs each Unity editor version in /Applications/Unity/Hub/Editor/<version>, with the platform modules you chose (iOS, Android, WebGL…). Each version is typically 5–15 GB with modules, and several often pile up over time.
Each installed Unity version with its platform modules. Keep the versions your projects use.
What happens if you delete it?
A removed version can be installed again from Unity Hub › Installs, which downloads it again. Projects that need it ask for it when opened.
How to remove it properly
In Unity Hub, open Installs, click the menu next to a version you no longer use, and choose Uninstall.
From the app itself: Remove from Unity Hub > Installs.
Before you delete it
Keep every version your projects are locked to; opening a project in a newer version may upgrade it.
How MoreRoom helps
MoreRoom recognises this item and labels it “Review first”: it shows what’s inside, its size and last use, so you can decide. Nothing is removed without your say, and everything goes to the Trash first, with Undo.
Frequently asked questions
Is it safe to delete Unity editor versions in Unity Hub?
Usually, after a check. Might hold something you care about. Look inside before removing it. A removed version can be installed again from Unity Hub › Installs, which downloads it again. Projects that need it ask for it when opened.
Will Unity editors come back after I delete it?
Yes. A removed version can be installed again from Unity Hub › Installs, which downloads it again. Projects that need it ask for it when opened.
How do I remove Unity editors properly?
In Unity Hub, open Installs, click the menu next to a version you no longer use, and choose Uninstall.