We studied the relative importance of objective local ethnolinguistic vitality (EV), the individual's network of linguistic contacts (INLC), and the individual's perceived language competences (in Swedish, i.e., L1 and in Finnish, i.e., L2) for ethnolinguistic identity among Swedish-speaking youth in three cities in southern Finland (N = 291). All adolescents were ninth-grade pupils at one of three schools in Ekenäs (N = 118), Borgå (N = 97), or Esbo (N = 76). We found that the identities studied — identification with Swedish-speaking Finns, with bilinguals, and with Finnish-speaking Finns — were predicted differently by local EV, INLC, and perceived L1 and L2 competence. Local EV had only a weak impact on ethnolinguistic identity. Regardless of the EV, perceived L2 competence did not subtract from identification with the Swedish-speaking Finns, while perceived L2 competence and a predominantly Finnish INLC increased identification with Finnish speakers and bilinguals, contributing to multiple ethnolioguistic identities. The different dimensions of ethnolinguistic identity studied, including national identity, were complexly interrelated in a pattern characterized by additive rather than by subtractive ethnolinguistic identities.