(Eastlake, Ohio, VS, 1975) Woont en werkt in Chicago, VS. William J. O’Brien heeft solotentoonstellingen gehad bij Shane Campbell Gallery, Oak Park (2010); bij Susanne Hilberry Gallery, Detroit; Marianne Boesky Gallery, New York (beide in 2009); The Axis Mundi, Shane Campbell Gallery, Chicago (2007); When Your Heart Is on Fire, Smoke Gets in Your Eyes, Locust Projects, Miami (2006); 12 x 12, New Artists, New York, Museum of Contemporary Art, Chicago; A Fairy Tale, Ingalls and Associates, Miami (beide in 2005). Groepstentoonstellingen zijn: Mystic Visage, World Class Boxing, Miami; At Home/Not Home: Works from the Collection of Martin and Rebecca Eisenberg, CCS Bard, Annandale-on-Hudson, New York (beide in 2010); Selected Works from the MCA Collection, Museum of Contemporary Art, Chicago; An Expanded Field of Possibilities, Santa Barbara Contemporary Arts Forum, Santa Barbara; Reskilling, Western Front Exhibitions, Vancouver, Canada (alle in 2009); Now You See It, Aspen Art Museum, Aspen (2008); So Wrong, I’m Right, Blum & Poe, Los Angeles; Stuff: International Contemporary Art from the Collection of Burt Aaron, Museum of Contemporary Art, Detroit (beide in 2007). O’Brien behaalde zijn MFA aan de School of the Art Institute of Chicago in 2005 en zijn BA aan de Loyola University Chicago.