School-day physical activity has been a long-standing focus because early learning settings shape children’s daily movement opportunities. However, few studies have examined these patterns in smaller, rural communities, where physical activity resources may differ. This study examined physical activity patterns among preschool children attending a Head Start program in a small town in the Great Plains of the United States, a region often underrepresented in scientific research. Eighty children were recruited; analyses included 60 children (23 boys, 37 girls; Mage = 49.98 ± 8.02 months) with valid accelerometry data (≥3 days during a typical 4-day school week). Children’s sex and age were recorded, and minutes spent sedentary and in light, moderate, and vigorous physical activity during the school day were assessed. Children accumulated 260.79 ± 22.21 min (66.87%) of sedentary time during the 390-min school day and spent 94.91 ± 19.04 min (24.33%; range = 58.29–149.80 min) in moderate-to-vigorous physical activity (MVPA). School-day minutes spent sedentary and in physical activity did not differ by sex and were not associated with age (p > .05). In regression analyses, sedentary time negatively predicted MVPA (B = −.232, t(57) = −2.308, p = .025), whereas moderate-intensity physical activity (MPA) positively predicted MVPA (B = .882, t(57) = 6.150, p < .001); the model explained 97.3% of the variance, F(2, 57) = 1030.015, p < .001. These findings suggest that children attending this Head Start program accumulated more MVPA during the school day than has typically been reported in the literature.