The growing prevalence of obesity among college-attending young adults is a major public health issue. Over one-third of U.S. college students are either overweight (23.3%) or obese (16.3%) (ACHA, 2017). This is problematic because overweight status during young adulthood is predictive of obesity in later life (Zheng et al., 2017). Thus, overweight and obese young adults face greater risk of developing chronic diseases, including more than half of the 15 leading causes of death in the U.S. The college milieu may be key to understanding obesity because it creates a distinct psychosocial context and shapes exposure to unique risks for young adults. Moreover, college students experience greater psychological distress compared to the general population, perhaps due to the stress associated with increased social and academic pressures. Given that distress has been linked with obesity and maladaptive health behaviors in prior research, enhancing psychological well-being may be an effective strategy to address the rising rates of obesity among college students. However, we still know relatively little about the distinct psychosocial and contextual risk and protective factors among this population. The purpose of this dissertation is to evaluate the contextual, psychosocial, and behavioral factors associated with obesity among college students at an ethnically diverse public university in Southern California. This will be investigated in three studies: Study 1 examines the extent to which social context and psychological distress are associated with increased odds of obesity among college students. Study 2 evaluates the role of lifestyle health behaviors in the relationship between distress and obesity. Study 3 assesses the ways that social relationships and eating habits shape comorbidity patterns in psychological distress and obesity among college students; a latent variable structural model is also used to explore these relationships. Findings from this dissertation may contribute to the limited, but growing body of literature on the nuanced relationship between psychological distress and obesity among college students. In addition, understanding how the college context distinguishes the health of this population may help campuses to create more tailored prevention and intervention programs that account for these psychosocial and contextual risk factors.