Marcus Jordan celebrated a big milestone this week … he just revealed Monday was the six-month anniversary of his sobriety.

Jordan noted the achievement in an Instagram post … writing in a caption, “6 Months Sober🚱🚯🚮 & Still The Life of The Party🥳 #180Days 🫡.”

He also included a carousel of recent pictures of him chilling with friends and hanging with his famous dad, Michael Jordan.

Marcus, of course, got sober following his now-infamous February run-in with police. You’ll recall, cops arrested him after they say he was drinking and driving — all with a baggie of ketamine on his person.

Jordan cut a deal with prosecutors last month to close the case out … and as part of his agreement with the officials, he said he would pen a 250-word “I’m sorry” letter to his arresting officer.