He was born in Chicago, IL, the son of Mattie, a housewife, and John Harris, a bus driver. He is the older brother of Wood Harris. He attended St. Joseph High School in Westchester, IL, a private school known for developing star athletes. Steve was a running back. He then played linebacker for Northern Illinois University, where he studied drama. His athletic career was cut short due to a torn ligament in his ankle.
He has done voice work for the animated television show The Batman as Ethan Bennett. He has also appeared on Law & Order and earlier had a role in Homicide: Life on the Street's pilot. In 2006, he appeared in the now-cancelled TV series Heist. He also appeared in an episode of Grey's Anatomy. He appeared in several episodes of New York Undercover. He has appeared in a number of films including; Quarantine, Tyler Perry's Diary of a Mad Black Woman, Bringing Down The House, The Rock, The Mod Squad, Takers, and Minority Report (with Neal McDonough and William Mapother).
Harris will star in actress Regina King's directorial debut Let The Church Say Amen which will be adapted from ReShonda Tate Billingsley's 2005 best selling novel. The film is scheduled to premiere on BET in 2013.