<p>Sociocultural factors and STEM identity have been previously shown to influence the success and mental health of students. Likewise, student identity influences persistence and can be protective of success and psychological distress in minoritized populations. This work sought to understand how sociocultural factors and mental health were related for STEM undergraduate students, with a specific focus on underrepresented minorities, and if elements of identity buffered these relationships. A survey of undergraduate students in STEM at two universities (<i>N</i> = 424) included measures of sociocultural factors (cultural congruity, everyday discrimination, and ethnic identity), psychological distress (anxiety, stress, and loneliness), and STEM identity. A bivariate correlation on all measures, a regression model for psychological distress and sociocultural factors, and a moderation analysis with identity as a moderating factor were presented. Results show that psychological distress in STEM students was adversely related to sociocultural factors, while elements of engineering and science identity were protective against certain aspects of psychological distress. Aspects of engineering identity also buffered the adverse effects of experiences of discrimination on anxiety for all students, while URM status adversely exacerbated these effects. The effect of sociocultural stressors on the psychological distress, namely anxiety, stress, and loneliness, of undergraduate students in STEM is presented. It is found that elements of engineering identity and underrepresented minority status can moderate the effects of discrimination and cultural congruity on psychological distress.</p>