Background: Sleep is increasingly recognized as a vital part of health. Screen time has been linked to sleep quality in children. The purpose of this study was to analyze associations between screen time and sleep characteristics among low-income preschoolers. Methods: A total of 1,700 preschool-aged children participated in this study at 50 federally and state-funded preschool centers in Michigan. Baseline measurement for an ongoing longitudinal intervention trial was obtained for cross-sectional use. At baseline, parents reported the number of hours their child spent engaging in screen time on a typical week day and weekend. An aggregate measure of total screen time was created. Parents reported on the quality of their child's sleep, how often they were tired during the day, and whether they had difficulty falling asleep. A mixed model linear regression was created to analyze data. Results: Controlling for child's age, race, and parental income, children who engaged in more screen time were significantly more likely to have more trouble falling or staying asleep, be tired during the day, and had worse quality of sleep (P values = .004, .006 and .001, respectively). Spearman correlations of screen time, sleep variables and demographics show parents of Black children reported significantly higher weekly screen time than parents of non-Black children (r = 0.23, P < .001) and that tiredness was associated with Black race (r = 0.15, P < .001), Hispanic/Latino ethnicity (r = −0.14, P < .001), and parental education (r = 0.06, P = .016). Conclusion: This report confirms prior associations between screen time and sleep reported in other pediatric populations. Further research is needed to confirm these results in other populations using more rigorous measures of screen time, sleep, and physical activity, as well as longitudinal assessments. Despite these limitations, findings suggest that interventions to help parents limit children's screen time and impact their sleep health merit investigation. (author abstract)