Scholars have identified that openness to diversity is a vital student outcome for higher education. Interest in this outcome has only intensified in recent years because of increased attention to, and unrest related to, social injustices. Using longitudinal data from 3420 undergraduate members of historically white college men's social fraternities located at 134 higher education institutions in the United States, this study examined factors that influenced the development of openness to diversity and change (ODC) amongst fraternity members from the 2019-2020 to 2020-2021 academic years. Our findings revealed that individual and institutional-level political and social involvement, and individual and institutional-level conceptualizations of fraternal brotherhood (e.g., brotherhood based on belonging) were associated with ODC during the 2020-2021 academic year. Though historically white college men's fraternities have often perpetuated exclusionary environments both in historical and contemporary times, the study results suggest that political and social involvement and participation in fraternities that emphasize belonging and accountability may contribute to college men's ODC. We urge scholars and practitioners to have more nuanced understandings of fraternities, while simultaneously challenging fraternities to put their values into actions and to deconstruct the legacies of exclusion that exist within these organizations.