Harry Joseph Lennix III is an American actor. He is known for his roles as Terrence "Dresser" Williams in the Robert Townsend film The Five Heartbeats (1991) and as Boyd Langton in the science-fiction series Dollhouse. Lennix co-stars as Harold Cooper, assistant director of the FBI Counterterrorism Division, on the NBC drama The Blacklist. Lennix has also played J'onn J'onzz / Martian Manhunter in the DC Extended Universe films Man of Steel, Batman v Superman: Dawn of Justice, and Zack Snyder's Justice League.

The Five Heartbeats is a 1991 musical drama film directed by Robert Townsend, who co-wrote the script with Keenen Ivory Wayans. Produced and distributed by 20th Century Fox, the film's main cast includes Townsend, Michael Wright, Leon Robinson, Harry J. Lennix, Tico Wells, Harold Nicholas, and Diahann Carroll. The plot of the film follows the three decade career of the rhythm and blues vocal group The Five Heartbeats. The film depicts the rise and fall of a Motown inspired soul act through the eyes of one of the Heartbeats, Donald "Duck" Matthews.