Abstract Introduction Sleep is crucial during early development to promote health, education, growth, and quality of life. Insufficient sleep is a public health problem, and this is clearly true for young children. The National Institutes of Health reported that preschoolers need 11-12 hours of sleep daily. We hypothesized that more physically active children would experience better sleep quality which would be associated with higher scores on cognitive and socioemotional measures. We also hypothesized that increased parental awareness of their child’s sleep patterns would predict more successful sleep health indicators in their children, leading to positive impact on preschoolers’ readiness to learn. Methods 82 preschoolers (ages 3-5) completed memory tests, a sleep hygiene scale, and a socioemotional assessment. Following initial cognitive and socioemotional testing, Fitbit devices collected activity and sleep measures for 12 weeks. Additionally, parents recorded bedtimes, wake times, total sleep time, naps, and activity levels in daily sleep journals. We assessed the association between physical activity and sleep quality, bedtime, wake time, memory, sleep hygiene, and socioemotional measures. Results Physical activity was positively associated with better sleep habits, including earlier bedtimes, earlier wake times, more consistent sleep-wake patterns, socioemotional scores, and working memory capacity. Higher child and parent sleep hygiene scales were associated with more consistent bedtimes. On average, the 82 preschoolers tested fell short of the recommended 11-12 hours of sleep per night. Conclusion Greater child and parent awareness of practicing good sleep hygiene increased the likelihood for the child to practice better sleep habits. Since physical activity was positively associated with sleep health measures, it is critical that parents and teachers prioritize sleep and activity in young children. Results of this study provide greater knowledge regarding associations between sleep, physical activity, and biopsychosocial outcomes that may be useful in implementing better education for parents and children geared toward improving sleep. Support This research was generously supported by the Caplan Foundation for Early Childhood and the Hope College Psychology Department.