This study examines belongingness as a strengths-based protective factor. Belongingness is investigated in relationship to the threat of low peer acceptance for loneliness and of high loneliness for depression in adolescents. Data were collected from peers for adolescents' peer acceptance and from adolescents themselves for other variables. Ratings of peers and self-reported survey data were analyzed together from data collected from 294 eighth-grade students from a culturally and ethnically diverse school. Results indicated belongingness was a significant moderator of the influence of peer acceptance on loneliness and of loneliness on depression. This suggests that belongingness is a potentially important buffer against the negative effects of low peer acceptance and high loneliness. Implications for counseling psychologists working with ethnically diverse adolescents are discussed. (Contains 2 tables and 2 figures.)