Adrien Broner is back behind bars in Cincinnati -- after the judge threw the book at the boxer for arriving to court more than 3 HOURS late.
Broner was due in court to deal with allegations he beat up a man outside of a bowling alley back in January. The case was expected to be dismissed today ... had Broner arrived to court on time.
But when he got there, the judge was PISSED -- and ordered him into custody immediately. The judge then ordered Broner to serve 30 days in jail for contempt of court.
Broner told the court that he thought someone had put something in his drink on Monday night -- which caused him to be late.
The judge said Broner appeared to be drunk or hungover.
He's due back in court on August 17th ... when he gets out of jail.