He hasn't fought in almost 15 years, but 53-year-old Mike Tyson can still hit like a Mack Truck ... and here's the video to prove it!!

Mike was hosting a bunch of UFC stars at Tyson Ranch earlier this month -- including Ottman Azaitar, a rising MMA star from Morocco.

During the meeting, Ottman and Tyson were talking about striking -- specifically a stick-and-move technique, when Mike decided it was time for the jacket to come off and the guns to come out.

Ya gotta watch the speed, power, footwork and movement ... it's still pretty damn impressive -- especially considering Mike has said he's stopped training, boxing, lifting weights etc. because it reminds him of the days when he was a monster.

But, maybe he's turning a corner ... and possibly thinking about coaching??

Of course, "Iron" Mike Tyson was 50-6 as a pro boxer -- with legendary victories over guys like Larry Holmes, Michael Spinks, Frank Bruno and Trevor Berbick.