The association between interpersonal relationships, perceived social support, and depressive symptoms in adolescents was investigated in the present study. The Center for Epidemiologic Studies Depressive Symptoms Scale (CES-D-SF), Multidimensional Scale of Perceived Social Support (MSPSS), and Interpersonal Relationship Scale (IRS) were administered to 1,573 high school students. There were four main findings: all three types of interpersonal relationships (same-sex peer, opposite-sex peer, and teacher--student relationship) and perceived social support had direct effects on depressive symptoms; perceived social support was a mediator in the relationship between interpersonal relationships and depressive symptoms; gender differences were present in the relationship between interpersonal relationships and depressive symptoms; and the three types of interpersonal relationships exerted different effects on depressive symptoms between adolescent boys and girls. Same-sex relationships exerted the strongest effect on depressive symptoms among girls, whereas teacher--student relationships exerted the strongest effect among boys.