He is known for his roles as Edward "Eddie" Sutton on ABC Family's Lincoln Heights, as Luke on the HBO drama In Treatment, as Detective Hank Griffin on the NBC series Grimm, and as Lyons in the movie Fences.

He also played Carl Gatewood in the Showtime TV series The Affair, and as Charles Flenory in BMF.

He was a football player and track star at St. Mary’s College High School in Berkeley, California.

After graduation, Hornsby continued his studies at the British American Drama Academy in Oxford.

[1] After finishing his studies at Oxford, Hornsby moved to New York City and was subsequently cast in leading roles in Off Broadway productions of To Kill a Mockingbird (as Atticus Finch), Joe Louis Blues, and Six Degrees of Separation (as Paul).