Public libraries are ideal contexts for supporting child development and family involvement (Families and Work Institute, 2015; IMLS, 2013). Families with children often attend public libraries to participate in educational programming and experiences, yet university-based developmental scientists who study how people develop and adapt across the lifespan have not fully recognized them as a significant context for the study of learning and development. This reflective essay suggests that developmental scientists and public libraries can achieve mutual benefits through joint research and evaluation efforts within the library context. We illustrate this type of collaboration through a firsthand account of a university–library partnership developed to support family engagement in library settings that promotes optimal parenting and enhances children’s school readiness.