Building on the Durkheimian legacy’s emphasis on social integration as a determinant of suicidal behavior, many macrolevel studies have observed an association between aggregate rates of geographical mobility and suicide, but little research has explored this connection at the individual level. We use data from 9,594 respondents who participated in two waves of the National Longitudinal Study of Adolescent Health to examine the effect of recent residential mobility on attempted suicide one year later and to explore the mechanisms that potentially transmit this effect. We find that among adolescent girls, recent movers are about 60 percent more likely than nonmovers to report having attempted suicide during the following year and that this difference cannot be readily explained by mover versus nonmover differences in preexisting demographic and family background characteristics. Some of the apparent effect of residential mobility on females’ risk of attempting suicide operates through higher rates of victimization and delinquency, lower levels of school attachment, higher rates of social isolation, and a tendency for movers to associate with peers who exhibit delinquent behaviors and who themselves have attempted suicide. In contrast, we find no evidence that mobile female adolescents’ deficit of parental social capital or lower levels of school engagement can account for the difference in attempted suicide risk between movers and nonmovers. We also find that residential mobility is not significantly associated with suicide attempts among adolescent males.