University life can be stressful and students may struggle to adjust socially. We examined students’ social achievement goals—their orientations towards their relationships with their peers—as one important factor underlying students’ social and psychological adjustment in college. When investigating the direct and indirect effects of social achievement goals on psychological adjustment (i.e., life satisfaction, depression, stress, and worry), the mediating role of emotion regulation was examined. Data were collected from students attending a university in China (N = 1,242, 35% male). The widely adopted three-factor structure of social achievement goals (i.e., social development goals, social demonstration-approach goals, social demonstration-avoidance goals) was confirmed to fit the data among Chinese college students. The results show the direct and indirect benefits of endorsing a social development goal. Augmented emotion regulation mediated the effect of social development goals. The total effects of a social demonstration-approach goal were weak, but the goal indirectly impaired students’ psychological adjustment via reduced emotion regulation. Endorsing a social demonstration-avoidance goal tended to compromise psychological adjustment and the effects were mediated through reduced emotion regulation. Implications for supporting students’ adjustment to college are discussed.