Open YouTube and sign in to your account
Find the channel or user you want to block
Open the channel page or go to one of their videos/comments
Select the user’s profile icon or channel name
Tap/click About (if available) or the three-dot menu (More options)
Choose Block user
Confirm the action to block the user
To unblock, go to YouTube Settings, then Privacy or Community, then Blocked users, and select Unblock