ObjectiveInformed by the family systems theory, the current study aimed to examine whether shared parental responsiveness between fathers and mothers with low income was associated with preschoolers' developmental outcomes.BackgroundBoth fathers' and mothers' parental responsiveness are key contributors to their young children's development. However, the ways in which fathers and mothers work as a system, as well as the role of shared parental responsiveness in child development, are not well understood, especially among families from low‐income contexts.MethodParticipants were from the Building Strong Families project, a racially diverse group of families from socioeconomically disadvantaged backgrounds (N = 1,173). Fathers' and mothers' parental responsiveness were observed during father–child and mother–child interactions using the two‐bags task. Preschoolers' child behavior problems, prosocial behaviors, and receptive language served as developmental outcomes of interest. A common fate approach to dyadic analysis was employed to create shared responsiveness and individual residual variance latent variables, which the child outcomes were regressed onto. Moderation analysis by fathers' resident status was conducted.ResultsShared responsiveness positively predicted preschoolers' prosocial behaviors (Β = 0.33, p < .001) and receptive language (Β = 14.85, p < .001), above and beyond individual residual variance. Fathers' resident status did not moderate any of the examined relationships.ConclusionThere may be benefits to young children's development when mothers and fathers demonstrate shared responsiveness.Implications.Interventions serving families with low income could help strengthen mother–father shared responsiveness to promote child development.