Simien was born on 7 May 1983 in Houston, Texas. He is the son of Anna Simien. Raised in the metro area, he attended the High School for the Performing and Visual Arts. After graduation he studied film at Chapman University in California. Simien worked a number of jobs in Los Angeles prior to directing his first feature film, including social media manager at Sony Television, publicity assistant at Focus Features, and publicity coordinator at Paramount Pictures.