While research supports later start times for secondary schools, there is little evidence regarding start times for elementary schools. We address this gap with a statewide examination of elementary schools and a quasi-experimental analysis of an urban district that recently changed its elementary start times. We find that earlier start times predict less sleep for students. Regarding academic outcomes, our estimates are small in magnitude and suggest that earlier elementary start times have near-zero effects. Earlier start times predict a slight increase in absences and modestly higher math scores, especially for traditionally disadvantaged students. In districts that need to stagger start times, it may be advisable for elementary schools to start earlier to accommodate later secondary school start times.