Michael Irvin -- I'm 46 ... AND I'M STILL RIPPED!!!

It's been 14 years since Dallas Cowboys superstar Michael Irvin hung up his cleats ... but the guy is still SHREDDED ... and last night, he proved it.

The 46-year-old Hall of Famer was outside of a party in New Orleans last night -- talking about his new vitamin company -- when he and our camera guy started braggin' about their physiques.

But Irvin -- always one to back up his talk -- lifted up his shirt and proved he's still got a killer 6-pack.