The short answer
No. Your data. Shrink it from its app; don’t delete the folder.
What is it?
The Photos Library package in your Pictures folder contains your photos and videos, edits, albums, people and memories, plus thumbnails. It is often the largest item in a home folder, from a few GB to several hundred GB.
Your photos and videos. Offload, or turn on Optimize Mac Storage in Photos > Settings > iCloud. Never deleted.
What happens if you delete it?
Nothing comes back if you delete it: photos that are not in iCloud Photos or a backup are lost. Only thumbnails and caches would be rebuilt, and they are a small part.
How to remove it properly
Do not delete it in Finder. If you use iCloud Photos, turn on Photos › Settings › iCloud › Optimize Mac Storage so full-size originals stay in iCloud and the Mac keeps smaller versions. Otherwise delete unwanted items in Photos and empty Recently Deleted, or move the whole library to an external drive with Photos closed and open it from there.
Better moved to an external drive than deleted.
Before you delete it
Make sure you have a backup first. Optimize Mac Storage is not a backup, and with iCloud Photos on, deleting in Photos removes items from all your devices.
How MoreRoom helps
MoreRoom recognises this as your data and never suggests deleting it. It shows how much space it takes, so you can shrink it from its own app.
Frequently asked questions
Can I delete my Photos Library to free up space on Mac?
No. Your data. Shrink it from its app; don’t delete the folder. Nothing comes back if you delete it: photos that are not in iCloud Photos or a backup are lost. Only thumbnails and caches would be rebuilt, and they are a small part.
Will Photos libraries come back after I delete it?
No. Nothing comes back if you delete it: photos that are not in iCloud Photos or a backup are lost. Only thumbnails and caches would be rebuilt, and they are a small part.
How do I remove Photos libraries properly?
Do not delete it in Finder. If you use iCloud Photos, turn on Photos › Settings › iCloud › Optimize Mac Storage so full-size originals stay in iCloud and the Mac keeps smaller versions. Otherwise delete unwanted items in Photos and empty Recently Deleted, or move the whole library to an external drive with Photos closed and open it from there.