Who? The heaviest I can honestly think of would be Chris Scharma, Magnus Midtbo, Jimmy Webb and maybe Jan Hojer, but all of them would be considered pretty skinny by normal standards. Scharma and Webb are probably around 6' 160-170 lbs, Jan is around 175 I think but he's 6'3", and Magnus is 5'8" and 158 lbs or so but has incredibly strong fingers.
Climbing is a strength to weight sport, so being heavier will almost always be worse than being lighter no matter what. It's why you don't see as many tall professional climbers as you would expect.
However, None of these guys are performing at a top level today, none of them have sent V16 or higher. Gill is the father of bouldering in America, and was setting standards from the 50s-70s, and claims the hardest problem he has done was about v10, at a time when no one else was anywhere near that good. Bouldering was a lonely pursuit in those days. He was able to hold one-arm levers and do one-pinky pull-ups.
Gill was also plagued by tendon pathologies in his elbows throughout his career, and those issues are more common amongst heavier climbers. Don't let that stop you from trying climbing if you're heavier, amongst mortals it's not such a big deal.
I put heavy in quotes, perhaps I should have put professional in quotes too.
Here is a larger climber who is sponsored by a lot of climbing companies: https://www.instagram.com/drewclimbswalls/?hl=en I'm not sure the extent to which he might be considered a professional, but having multiple sponsorships suggests it's semi-professional for him.
He's not pushing the limits of the sport, but he's promoting a more inclusive attitude. Climbing for a lot of people is about having fun, and very few people will send the hardest climbs, but you can be professional without being elite.
Who? The heaviest I can honestly think of would be Chris Scharma, Magnus Midtbo, Jimmy Webb and maybe Jan Hojer, but all of them would be considered pretty skinny by normal standards. Scharma and Webb are probably around 6' 160-170 lbs, Jan is around 175 I think but he's 6'3", and Magnus is 5'8" and 158 lbs or so but has incredibly strong fingers.
Climbing is a strength to weight sport, so being heavier will almost always be worse than being lighter no matter what. It's why you don't see as many tall professional climbers as you would expect.