Along with recent changes in cannabis legalization and decriminalization, there has been an increasing amount of attention aimed at cannabis use and outcomes in college. Although some amount of cannabis use might be expected under theories of collegiate identity development, public health research indicates that cannabis use ultimately associates with negative vocational outcomes. To examine how cannabis use associates with college grade point average specifically, we surveyed n?=?1,080 full-time college students and a replication sample of n?=?590. Results showed that even after accounting for other measures of student identity formation and drug use, increased cannabis use was robustly associated with lower grade point average. Future research should examine the mechanisms underlying this association. Nevertheless, while laws and attitudes toward cannabis evolve, initiatives to decrease college use should continue.