William Fitzgerald Harper was born on February 8, 1980, in Dallas, Texas. He graduated from the Santa Fe University of Art and Design in 2003.
From 2009–2011, Harper starred in the PBS children's series The Electric Company.
Harper made his Broadway debut in 2014, cast as James Harrison and Stokely Carmichael in All the Way.
In 2016, Harper was cast on the NBC comedy The Good Place. Before landing the role, he considered quitting acting. Harper did not learn about the show's real premise until after he was cast. His performance has received critical praise. In 2017, in between filming seasons of The Good Place, he had a leading role in Zoe Kazan's After the Blast at Lincon Center's Claire Tow Theatre.
