Faison was born in Harlem in New York City, the son of Shirley, a talent agent, and Donald Faison, a building manager. He is the elder brother of actor Olamide Faison. His middle name stems from the words "ade" (meaning "crown") and "osun" (meaning "river of life”) in the west African language of Yoruba. His parents were active with the National Black Theater in Harlem. He attended the Professional Children's School in Manhattan with his best friend, actor Dash Mihok.