The impact of attachment to fathers on mental health in Latinx communities is understudied and not fully understood, though extant research focusing on maternal attachment forms a solid base of knowledge regarding the importance of attachment (to mothers) on mental health. The broad aim of this study was to examine the importance of paternal attachment in relation to maternal attachment on mental health in Latinx young adults. The current study used two large, young adult samples: one collected in Latin America ( n = 774) and one collected in the United States ( n = 1084). We hypothesized that paternal attachment would be a significant predictor of internalizing (emotional symptoms), externalizing (hyperactivity, conduct problems), and interpersonal (social problems, prosocial behavior) functioning beyond maternal attachment. Exploratory analyses examined whether paternal communication, trust, or feelings of alienation, three established facets of attachment, differentially related to mental health outcomes. Findings broadly supported hypotheses, as attachment to fathers made a significant, incremental contribution to all outcome variables. Further, paternal alienation emerged as a potent potential risk factor, while paternal trust emerged as a potential protective factor for mental health outcomes in these samples. This study is the first to endeavor to understand the links between paternal attachment and mental health beyond maternal attachment in two distinct samples with varying immigration statuses, countries of residence, and cultural norms and has important implications for working with Latinx populations from a clinical, assessment, and research standpoint.