Jeremy Allen White Rocks Calvin Klein Underwear As Brand's Newest Model

Jeremy Allen White is the new Marky Mark -- no, he's not rapping about "Good Vibrations," but he sure as hell looks hot in the same undies Wahlberg used to rock on larger than life billboards.

The actor launched his partnership with Calvin Klein Thursday with a set of steamy photos of him in the signature white briefs -- showing off his shredded physique.

BTW, looks like he did the shoot -- or at least, part of it -- on a rooftop in NYC, which happens to be his hometown.

JAW's got a lot going for him right now, so this ambassador gig is the icing on the cake -- as you know, he's garnering Oscar buzz for his role as Kerry Von Erich in "The Iron Claw," and he's up for a Best Actor Golden Globe this weekend for his work in "The Bear."

Things also seem to be going well for him in the dating department ... 'cause he was spotted taking a stroll in NYC with his boo, Rosalía, last week.