This study explores the relative contribution of parental and teacher support to adolescents' psychosomatic health complaints, with a particular focus on gender and age differences. Based on a survey of 49,172 ninth- and eleventh-grade students in Stockholm (2006–2014), structural equation modeling results demonstrated negative associations between parental and teacher support on psychosomatic health complaints. Parental support had a stronger association with the outcome among girls than boys. It was also more important than teacher support for psychosomatic health complaints. Parental support was more important for younger girls' health compared to older girls, with opposite patterns for teacher support. These findings highlight the need to consider gender and age to understand the links between social support and health during adolescence.