My Ryobi drill has a bit stuck in the chuck and it wont come loose, what do i do?

You can get the entire chuck off by holding the motor. The easiest way to do this is jam something into the cooling vanes. After that, just turn the entire chuck CCW. You should be able to get this off with just your hands, but you can use channel lock pliers if needed.

You could also try holding the snug ring with one set of pliers and turning the chuck with another. But first, just spray the mechanism with some Liquid Wrench and let it penetrate. It will probably loosen up to where you don’t have to do anything drastic.

i am having the same problem, did it work for you?

WARNING: Please be sure to unplug the drill before you do anything like that. It sounds like @IchtheosaurusRex has a good plan. I used it with an older Black & Decker when that happened to me some years ago.

I found that the screw inside of the chuck had loosened and was binding the chuck. I was able to open the chuck enough to get a screwdriver in and tighten the screw (left hand thread). Problem solved.
BTW – the suggestion to use a large allen wrench, locked into the chuck, to break the thread loose was excellent!