Leon participated in the federally funded TRIO Upward Bound college-prep program while in high school.

[3] During Leon's tenure, the company staged premieres of Pearl Cleage's Blues for an Alabama Sky, Alfred Uhry's The Last Night of Ballyhoo, and Elton John and Tim Rice's musical Aida, which went on to Broadway.

These included being the co-founder and artistic director of True Colors Theatre Company,[4] a group based in both Atlanta and Washington, D.C.

In the spring of 2004, he directed a revival of Lorraine Hansberry's A Raisin in the Sun, starring Sean Combs, Phylicia Rashad and Audra McDonald, in his Broadway debut.

In November 2010, Leon directed Phylicia Rashad in the world premiere stage play Every Tongue Confess written by Marcus Gardley, which ran at the Arena Stage in Washington, D.C. Leon has also directed plays at the Cincinnati Playhouse in the Park, the Huntington Theatre Company in Boston, the New York Shakespeare Festival, the Goodman Theatre in Chicago, and other venues.

[1] Other projects at that time included the world premiere of a staged adaptation of the 1967 film Guess Who's Coming to Dinner at the Kenny Leon's True Colors Theatre Company; and a musical inspired by the work of rapper Tupac Shakur.

[6] That same year Leon directed NPR Presents Water±, written by award-winning NPR Science Correspondent Christopher Joyce, and award-winning theater writers Arthur Yorinks and Carl Hancock Rux, with an original sound score by violinist Daniel Bernard Roumain (DBR).

[8] In 2016, Leon once again partnered with NBC for Hairspray Live!, starring Ariana Grande, Jennifer Hudson, Kristin Chenoweth, and Harvey Fierstein.

He made an appearance in the Hollywood Black Film Festival winner Big Ain't Bad, playing the role of Thomas Jordan, the mayor of Atlanta.

He also directed The Underlying Chris at Second Stage Theatre Company and summer 2019's acclaimed production of Much Ado About Nothing at the Delacorte/Shakespeare in the Park.