A heterogeneous student body is valued in part because diverse interactions among students help create educated and competent citizens and promote learning and development. Campus housing is a primary setting for diverse interactions as students navigate living with individuals who differ from themselves. This study investigated how the roommate assignment process influences interactional diversity and perceptions of the campus environment for first-year students living on campus, and if these relationships differ by race/ethnicity and national origin. On average, students whose roommates were assigned by the institution (as opposed to choosing their own roommates) did not interact with diverse others more often. At the same time, however, Asian, Black and multiracial students who were assigned roommates by the institution perceived a substantially less welcoming campus environment than their same-race peers who chose their roommates. This difference was not observed for White students.