Objectives: Physical activity can be promoted by high levels of gross motor skills. A systematic review found a positive relationship in children (3–18 years) but only few studies examined this in younger children. The aim of this study was to examine the association between gross motor skills and physical activity in children aged 11–29 months. Design: Cross-sectional study. Methods: This study involved 284 children from 30 childcare services in NSW, Australia (Mean age = 19.77 ± 4.18 months, 53.2% boys). Physical activity was measured using accelerometers (Actigraph GT3X+). Gross motor skills were assessed using the Peabody Developmental Motor Scales Second Edition (PDMS-2). Multilevel linear regression analyses were computed to assess associations between gross motor skills and physical activity, adjusting for sex, age and BMI. Results: Children spent 53.08% of their time in physical activity and 10.39% in moderate to vigorous physical activity (MVPA). Boys had higher total physical activity (p < 0.01) and MVPA (p < 0.01) than girls. The average gross motor skills score was 96.16. Boys scored higher than girls in object manipulation (p < 0.001). There was no association between gross motor skills and total physical activity or MVPA. Conclusions: Although gross motor skills were not associated with physical activity in this sample, stronger associations are apparent in older children. This study therefore highlights a potential important age to promote gross motor skills.