Floyd Mayweather Sr. is now a married man -- TMZ Sports has learned the 65-year-old tied the knot in a low-key ceremony back in February ... and we've got the pics to prove it!
Sources connected to the situation tell us ... Floyd and Lois Ann Roberts hit up the Stained Glass Wedding Chapel in Vegas on February 4 and swapped "I Dos" in a very quick and quiet ceremony.
The place offers special Elvis-themed weddings -- but Floyd opted for the more traditional option.