Despite the detrimental consequences of child maltreatment on developmental processes, some individuals show remarkable resilience, with few signs of psychopathology, while others succumb to dysfunction. Given that oxytocin has been shown to be involved in social affiliation, attachment, social support, trust, empathy, and other social or reproductive behaviors, we chose to examine the possible moderation of maltreatment effects on perceived social support and on psychological symptoms by a common single nucleotide polymorphism (rs53576) in the oxytocin receptor gene. We studied adolescents (N = 425) aged approximately 13–15, including participants with objectively documented maltreatment histories (N = 263) and a nonmaltreated comparison group from a comparable low socioeconomic status background (N = 162). There was a significant genotype by maltreatment interaction, such that maltreated adolescents with the G/G genotype perceived significantly lower social support compared to maltreated A-carriers, with no effect of genotype in the comparison group. Maltreated G/Gs also reported higher levels of internalizing symptoms than did A-carriers, even though they did not differ from them on objective measures of maltreatment (type, duration, or severity). G/G homozygotes may be more attuned to negative social experiences, such as family maltreatment, while maltreated A-carriers were indistinguishable from nonmaltreated adolescents in levels of mental health symptoms.