"Oh, she's gonna be a big star," the WWE Hall of Famer told us at LAX ... "It's inevitable. I see her in a WrestleMania someday."
Rousey's been a huge pro wrestling fan for years -- and there have been rumors that she could follow in the footsteps of guys like Ken Shamrock and make the transition from the UFC to WWE.
Ross thinks that's 100% the right move.
"It's too great an opportunity for her to pass up and WWE to pass up ... it's a match made in heaven."