Understanding socio-cultural factors associated with the development of dieting tendencies is important for preventing future disordered eating. We explored individual and socio-cultural factors associated with weight-focussed dietary restraint tendencies (described as dietary restraint) in 5-year-old girls.Participants were 111 5-year-old girls and 109 of their mothers. Girls were interviewed about their dietary restraint, body image, appearance ideals, positive weight bias (attributing positive characteristics to thinner figures), and peer conversations. Mothers completed self-report questionnaires assessing dietary restraint and appearance ideals, as well as measures reporting on their daughter's media exposure and peer appearance interest.Thirty-four percent of girls reported at least a moderate level of dietary restraint. While most girls were satisfied with their body size, half showed some internalization of the thin ideal. Girls' dietary restraint was correlated with weight bias favoring thinner bodies, and greater internalization of the thin ideal, media exposure, and appearance conversations with peers. Media exposure and appearance conversations were the strongest predictors of dietary restraint.These cross-sectional findings suggest that the socio-cultural environment of young girls may be important in the very early development of unhealthy dieting tendencies. Longitudinal research is necessary to identify whether these are prospective risk factors.