Dennis Rodman has been charged with misdemeanor battery in Florida for allegedly slapping a man at his own birthday party back in May -- but The Worm is adamant he's innocent.
TMZ Sports broke the story ... cops say Rodman was at the Buddha Sky Bar in Delray Beach on May 17 when he "unprovokedly turned around and smacked" 30-year-old Jeff Soulouque.
Soulouque claims Rodman immediately began apologizing for the incident and invited him out to dinner the following night in an attempted peace offering.
But, Soulouque told TMZ Sports he was really hurt -- and went to the hospital where he was diagnosed with a left corneal abrasion. He went to cops the day after the incident and filed a report.
Cops launched an investigation and called up a witness named David Lee Roth -- who, shockingly, is NOT the Van Halen singer. Still, cops say DLR corroborated Soulouque's story.
"Roth stated he was about twenty feet away and he saw Rodman turn around and open hand smack Soulouque two times," the report states.
Prosecutors later charged Rodman with misdemeanor battery -- and on Thursday, DR's attorney appeared in court on his behalf and pled not guilty.
It's a big deal for Rodman -- the charge carries a maximum sentence of a year in jail, 12 months probation and a $1,000 fine.
And, with Dennis' criminal history, it's possible a judge could throw the book at the NBA legend if he's convicted.
We're out to Rodman's reps for comment -- so far, no word back.