The rapper, whose real name is Antwan Patton, was sentenced in a Miami court Thursday.
The 36-year-old was arrested back in August after custom officials discovered drugs on the rapper as he was getting off a cruise ship. The substances included ecstasy, a cigarette roller with marijuana residue and the ecstasy ingredient MDMA.
A judge ordered Patton to three months of drug testing, 15 hours of community service and $2,000 in donations to charities.
Patton had faced two felony drug charges. Prosecutors say if he remains drug-free after three months of testing, those charges will be dismissed.
The Atlanta-based group OutKast has won six Grammys and made six platinum-plus albums, including "Speakerboxxx/The Love Below."
The Associated Press contributed to this report.