Chief Keef Sentenced To 90 Days In Jail Rehab

Chief Keef is headed back to jail ... and proudly blasted the news out to the world after a judge slapped him with a 90 day sentence.

Keef, aka Keith Cozart, tweeted ... "Judge Putting me Back in jail See y'all later."

A Chicago judge sent Keef to a jail rehab facility because he reportedly failed a random drug test.

The 18-year-old rapper gets tested as part of his probation for a speeding ticket -- cops clocked him doing 110 mph in a 55, back in May.

This is Chief's second F on a drug test -- just last month he got 20 days in jail, but was released 11 days early due to jail overcrowding.

Update: Chief Keef has failed 3 random drug tests ... and each time tested positive for marijuana. Keef was sentenced yesterday to a drug rehab facility ... but he's currently being held in the Cook County jail until he can be transferred to the rehab center.

This ni**a always going to jail!

SOURCE