Jermell Charlo Vows to Sue Gym Over Alleged Racial Incident

Boxing champ Jermell Charlo is convinced he was banned from working out at a fancy NYC gym because he's black -- and now he's threatening to sue the hell out of them.

TMZ Sports spoke with Charlo who's still VERY pissed over what went down at Life Time Athletic Fitness in Manhattan on Thursday night ... when he and his crew were told they would NOT be allowed inside.

Charlo says they showed up to work out with his brother, boxing star Jermall Charlo -- who was already inside the building -- but the gym staff refused to let the crew purchase a day pass.

Charlo claims his crew was falsely accused of smelling like weed. He believes the real reason they were turned away is because he's "a black man."

Cops were called to the gym but no arrests were made.

Jermell says he doesn't want an apology -- he wants revenge in court -- because he wants the whole world to see what happened to him.