Social development and stress process theories suggest that participation in one's community can function as a protective factor for mental health, especially for youth from socioeconomically disadvantaged areas. However, the effects of community involvement on adolescent mental health could vary across racial/ethnic groups and levels of neighborhood disadvantage. The objectives of this paper are to: (1) examine the effects of various types of community involvement on adolescent mental health, and (2) assess the extent to which race/ethnicity and neighborhood disadvantage moderate the effects of community involvement on adolescent mental health. Using data from two waves (1994/95 and 1996) of the National Longitudinal Study of Adolescent Health ("Add Health," N = 7,863), multilevel (hierarchical) linear models were estimated that tested for interaction effects of race/ethnicity and neighborhood disadvantage. The types of community participation that impacted adolescent mental health varied across racial/ethnic groups. Neighborhood interaction and religious participation were salient for both White and Hispanic teens, but the impact of religious participation for Whites was moderated by neighborhood disadvantage. Non-sport extracurricular activities and employment were the salient factors for Black teens, both of which were moderated by neighborhood disadvantage. The findings from this study have implications for community-level and clinical interventions to prevent and/or treat mental health problems among adolescents. Social integration interventions should take into account adolescents' cultural backgrounds and socioeconomic contexts in order to be effective. (Contains 4 tables.)