Adequate sleep is essential for child learning. However, school systems may inadvertently be promoting sleep deprivation through early school start times. The current study examines the potential implications of early school start times for standardized test scores in public elementary schools in Kentucky. Associations between early school start time and poorer school performance were observed primarily for schools serving few students who qualify for free or reduced-cost lunches. Associations were controlled for teacher-student ratio, racial composition, and whether the school was in the Appalachian region. Findings support the growing body of research showing that early school start times may influence student learning but offer some of the first evidence that this influence may occur for elementary school children and depend on school characteristics.