Jonathan Majors is getting some major love from his "Magazine Dreams" costar Mike O’Hearn -- who says Majors crushed it in the bodybuilding flick.

We ran into Mike at Gold’s Gym in Venice Beach Monday, and he didn’t hold back -- saying Jonathan could easily snag a Mr. Universe title ... but says Jonathan's real gift is acting, and the world needs him on the big screen.

Check out the clip -- Mike’s all praises for JM, saying he absolutely deserves the hype for the movie, which is out now.

The actor and bodybuilder also gets real about JM's rough year following his 2023 guilty verdict for assaulting ex Grace Jabbari -- offering a message of grace and the opportunity for second chances.

As for the movie, Mike says the bodybuilding world is flooding him with love -- and he even thinks it’s special enough to snag an Oscar.

Quick rewind to JM ... he's got a bunch of pals lifting him up -- weightlifting legend Ronnie Coleman recently vouched for him, saying he was in top shape and could totally be a bodybuilder after their grueling workout together!