Although social marketing principles have been successfully employed in school-based obesity prevention interventions, their use in early care and education (ECE) settings has been limited. This paper reports on formative research to develop Healthy Me, Healthy We (HMHW), an innovative social marketing campaign that encourages partnership between parents and providers to foster healthy eating and physical activity in preschoolers. To guide campaign development, we consulted existing literature and identified useful theories. In addition, three focus groups with providers (n = 17) and four with parents (n = 20) were conducted to understand strategies used to instill healthy habits in children, perceptions of how their personal behaviors influence children, and the usefulness of parent-provider partnerships. Parents and providers recognized healthy eating and physical activity as important to the development of the "whole child." Both groups expressed feeling great responsibility for shaping children’ habits and being a role model for healthy behaviors, particularly for healthy eating. While parents and providers felt partnership was important, areas of conflict emerged with how partnerships should be executed. There is great potential for such partnerships, but careful communication is needed to avoid triggering feelings of guilt among parents and perceptions of superiority among providers. These findings informed campaign development, which was pretested in an ECE setting. The resulting HMHW campaign is delivered by the childcare center and includes materials for classroom and home use. The campaign helps strengthen parent–provider partnerships to encourage healthy eating and physical activity habits during early childhood, a critical period in the development of lifelong health habits. (author abstract)