Research has indicated that people who are more open to novel and diverse experiences express less prejudicial views concerning minority group members. The openness-prejudice relationship, however, may be mediated by the degree to which individuals adhere to traditional social convention and absolutist thinking patterns. Thus, informed by the Dual-Process Cognitive-Motivational Model of ideology and prejudice (Duckitt, 2001; Duckitt & Sibley, 2009) and the Five-Factor Model of personality (Costa & McCrae, 1992; McCrae & Costa, 2003), we investigated right-wing authoritarianism (RWA) as a mediator of the relationship between openness and antigay prejudice. Participants were college students from universities in the mid-Atlantic (Sample 1, n = 199) and southeastern (Sample 2, n = 244) United States. Hypotheses were tested in both samples. First, bivariate relations among openness, RWA, and antigay prejudice were assessed. Second, RWA was tested was a mediator of the relationship between openness and antigay prejudice. Results supported expected bivariate associations in that openness negatively, and RWA positively, associated with antigay prejudice. Moreover, results showed that RWA mediates the negative relationship between openness and antigay prejudice. Implications of the supported model are discussed with respect to antigay prejudice theory as well as prejudice-reduction interventions for use on college campuses. (Contains 4 tables and 1 figure.)