Brian Banks -- Exonerated NFL Player ... I'M GETTIN' MARRIED!!!

Another milestone for Brian Banks -- the football star who made it to the NFL after proving he was wrongly convicted of rape ... 'cause TMZ Sports has learned he's getting married ... TOMORROW!!!

Brian's story is incredible ... he was a high school football superstar who spent 5 years in prison for a crime he didn't commit. Then, after he proved his accuser made the whole thing up, he battled his way in to the Atlanta Falcons training camp in 2013 and actually played in some pre-season games!

Now, we've learned... the 29-year-old is all set to tie the knot with his fiancee Emmy -- and it's all going down in Vegas. The two have been together for 3 years.

We're told the ceremony will be pretty small -- just close friends and family -- but there will be a few famous faces in the crowd ... including NFL insider Jay Glazer and former UFC fighter Frank Trigg.

And get this ... Banks became close with an officer in the Navy during some of the USO/NFL tours he did recently ... and we're told the officer has a cool gift in store for Brian.

He's going to fly the USA flag over Camp Lemonnier during the moment of Brian's "I Do's" ... and told Brian it's because, "Lives with meaning like yours are worth fighting for. You deserve the best."

Congrats!!!