Background: National data demonstrate significant differences in non-medical prescription drug (NMPD) use, with Whites seeming to be more likely to use compared to non-Whites. College students also appear to be at an increased risk for NMPD use. Objectives: This study examines NMPD use using a component of social identity theory. We propose that a stronger sense of ethnic identity may reduce the likelihood of NMPD use among college students due to ethnic identity’s ties to self-esteem and self-efficacy. We also propose that the protective power of ethnic identity may vary according to one’s race. Methods: Data for this study were collected from a survey of undergraduate students at a Midwestern university (N = 530). Poisson regression analyses were used to test the relationship between ethnic identity and NMPD use. Of our sample, 135 participants (25.5%) indicated NMPD use over the past year. This percentage is high compared to findings from national college data. Results: Results indicate that a stronger sense of ethnic identity reduced the frequency of NMPD use among young adults. The findings also reveal that the relationship between ethnic identity and NMPD use is moderated by race. Ethnic identity was found to be a protective factor for non-White participants only. Conclusions: This study suggests that ethnic belonging may act as a protective factor against NMPD use among non-White young adults. These findings build upon our understanding of the relationship between ethnic identity and substance use. We conclude with a discussion of directions for future research and intervention programs