Allen, a 6-foot-7 sophomore from Dallas, appeared in 22 games this season and averaged 2 points and 1.9 rebounds.
"D'Angelo Allen has made it known to the Mizzou Men's Basketball program his intention to transfer, and we will support his request," coach Kim Anderson said Monday in a release. "D'Angelo and I met and he expressed his desire to play a larger role. We agreed he can begin to seek opportunities to achieve his goals elsewhere. We appreciate D'Angelo's contributions during his time with the program and will work to assist him in any way possible."
Allen averaged 3.3 points and 3.1 rebounds in 17 minutes per game during his freshman campaign.
Allen joins Jonathan Williams III and Montaque Gill-Caesar as the third Missouri player to transfer in the past year.