While lack of social support for adolescent mothers has been tied to parenting stress and postpartum depression, the types of support received by adolescent mothers from their mothers and the fathers of their babies (FOBs) and changes in this support over time have not been thoroughly characterized. We performed a secondary analysis of data from a randomized controlled trial of 106 adolescents at an urban prenatal clinic between February 2007 and August 2008. Information on social support was collected at 20–24 weeks gestation, in the hospital after delivery, and at 6-weeks, 3-months, and 6-months postpartum using the Arizona Social Support Interview Schedule. We assessed the amount and types of support provided by mothers and FOBs, compared support between mothers and FOBs and assessed changes in support over time. The prevalence of support for adolescent mothers from their mothers and FOBs was similar, but FOBs provided more types of support compared with mothers at specific time points. Support from mothers peaked after delivery, whereas support from FOBs remained stable over time. FOBs provided more social-type support and intimate support than mothers did but were also frequently a source of social strain. Adolescent mothers’ FOBs and mothers have unique roles to play in their support networks. Understanding patterns of social support for adolescent mothers has the potential to inform future interventions to augment support for this vulnerable population, and, as a result, to influence maternal and early childhood health outcomes.