Objective: This study evaluated the potential of youth partnerships to improve the school environment and child nutrition. Methods: A quasi-experimental trial was conducted with 2 intervention and 3 control schools. Intervention schools selected student leaders to participate in youth-led interventions in their schools. Students (n = 104) were included in the evaluation if they were in the fourth grade at baseline and had complete baseline and follow-up data. The intervention trained student leaders in research, advocacy, and nutrition. Leaders implemented interventions appropriate to their schools. Changes in children's reported dietary intake were examined. Data were analyzed using multivariable regression. Results: Children's diets changed in response to the interventions offered at the schools, although the dietary changes differed by the types of interventions selected. Conclusions and Implications: Partnering with youth, even at the elementary school level, is a promising avenue for developing tailored interventions for schools. (Contains 2 tables.)