Actor Desmond Harrington found it difficult to stay in school during his teenage years as trouble seemed to follow him around. He studied at Manhattan college but his education there was only short-lived. After dropping out, he landed odd jobs, which eventually led him to attend an acting class and sparked his interest in the world of show business.
Harrington made his movie debut in 1999 in The Messenger: The Story of Joan of Arc. This was followed by roles in Boiler Room, Drop Back Ten, Riding in Cars with Boys, The Hole, Ghost Ship and We Were Soldiers starring Mel Gibson. Though he continued to be visible in the big screen through Love Object, Wrong Turn, Taphephobia, Exit Speed and Life Is Hot in Cracktown, he also started to make waves on the small screen. After appearing in three episodes of Taken, he starred as Det. Jimmy McCarron on the TV series Dragnet, in which he appeared for 10 episodes. In 2006, he was also cast as Wylie Blake on Sons & Daughters, followed by a recurring role on Rescue Me as Troy.
In 2008, Harrington landed the role of Joey Quinn on the Showtime series Dexter, which is his biggest role thus far. Subsequently, he was cast as Jack Bass on the CW's Gossip Girl.