Fields will enroll Aug. 4, he said in a text to ESPN.com. Louisville is scheduled to begin fall practice two days later.
On Tuesday, Louisville coach Bobby Petrino told reporters at the ACC Kickoff the school was still waiting on certification before Fields could enroll.
The former Big 12 Defensive Player of the Year at TCU, Fields received clearance from UL's admissions department on Wednesday afternoon.
Fields was ESPN's No. 2 rated junior college recruit at Trinity Valley Community College last year, where he spent one season after being dismissed from TCU.
The misdemeanor assault charge he faced for allegedly hitting an ex-girlfriend last July was recently dropped after Fields completed an anger-management program.