Open YouTube
Go to the channel you want to block
Click the channel name or profile picture
Open the channel menu
Select Block user or Hide user from channel options if available
On a video from that channel, click the three dots
Select Not interested or Don’t recommend channel
On YouTube comments, click the three dots next to the user
Select Hide user from channel
On mobile, tap the channel profile
Tap the three dots in the top right
Select Block user if available
Use browser extensions or parental controls if you need stronger blocking
Report the channel if it violates YouTube policies