Miles the Broncos Mascot -- Peyton Will Retire ... If We Win the Super Bowl!!

Here's some Peyton Manning news ... straight from the horse's mouth.

"Miles," the official Broncos mascot, tells TMZ Sports ... he believes Peyton will finally hang up his cleats for good if the team hoists the Lombardi Trophy at the end of Super Bowl 50.

Well, he didn't actually "say" that -- 'cause he can't talk -- but he definitely used hand signals to convey the message.

BONUS -- we also asked if he had a dance move to compete with Cam Newton's dab ... and he totally does!!