Steve-O baldly went where no stuntman has gone before -- courtesy of Mark Wahlberg himself, who took clippers to his head, all in honor of Mark's latest movie role.

MW's playing a balding hitman in "Flight Risk," and Steve-O wanted in on the look. So, the actor went full barber mode, and you can watch the transformation in this "Wildride! with Steve-O" clip.

Steve-O going all in on the wild look was totally on brand. Meanwhile, Mark was clearly loving his side gig as a hairstylist -- who knew Wahlberg had shear talent?

Of course, Steve-O's just following Mark’s lead -- because Wahlberg didn’t fake it with a bald cap either! He fully committed, shaving his head for "Flight Risk," which also stars Michelle Dockery and Topher Grace. Catch it in theaters January 24!