William J. O'Brien (b. 1975, United States) is a Chicago-based artist whose improvised studio practice begins with drawing and extends to other mediums of painting, sculpture, and ceramics. Through the intuitive use of gestural mark, repetition, and material, O'Brien transmutes painful or difficult aspects of personal and social history through visual expression. He received a BA from Loyola University Chicago and MFA from the School of the Art Institute of Chicago.