The short answer
Usually, after a check. Might hold something you care about. Look inside before removing it.
What is it?
Telegram Desktop, the cross-platform client distinct from the native Telegram for macOS, keeps its cached media and your login session in ~/Library/Application Support/Telegram Desktop. The cache ranges from hundreds of MB to tens of GB.
Mostly cached media, plus your session. Clear the cache from the app; deleting the folder signs you out.
What happens if you delete it?
Cached media downloads again from Telegram’s cloud. Deleting the whole folder signs you out and resets local settings.
How to remove it properly
In Telegram Desktop, open Settings › Advanced › Manage local storage and clear the cache, or lower the cache limits there.
From the app itself: Telegram Desktop > Settings > Advanced > Manage local storage.
Before you delete it
If you delete the folder instead, keep your phone at hand to log in again.
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 Telegram Desktop’s data folder?
Usually, after a check. Might hold something you care about. Look inside before removing it. Cached media downloads again from Telegram’s cloud. Deleting the whole folder signs you out and resets local settings.
Will Telegram Desktop data come back after I delete it?
Yes. Cached media downloads again from Telegram’s cloud. Deleting the whole folder signs you out and resets local settings.
How do I remove Telegram Desktop data properly?
In Telegram Desktop, open Settings › Advanced › Manage local storage and clear the cache, or lower the cache limits there.