Although substance use is considered normative in college, continued examination of factors associated with problematic use is merited. This study identified latent substance user classes and examined their relations with sex, race/ethnicity, impulsivity-like facets, and substance use outcomes among 702 undergraduate students. Non-Alcohol Abstaining Users (NAA), Minimal Users (MU), and Polysubstance Users (PSU) emerged from latent class analysis. Variable-centered analyses indicated that substance user classes did not differ by sex. Students in the Asian and Other groups were at greater odds of being in the MU class than either NAA or PSU class, compared to White students. Differential patterns of impulsigenic trait levels emerged across latent classes. The present study highlights the utility of integrating person- and variable-centered approaches in studying heterogeneous substance use behaviors among college students. College PSU are particularly at risk for problematic outcomes, thus warranting preventive intervention that may target impulsigenic traits or polysubstance use.