ObjectiveThe present study probes into the association between children's fundamental movement skills (FMS) and moderate‐to‐vigorous physical activity (MVPA) during weekdays and weekends.MethodsThis cross‐sectional sample included 1014 children aged 6–10 years from the REACT project. Physical activity was assessed with accelerometry, and five FMS (stationary dribble, kick, catch, overhand throw, and underhand roll) were assessed with the digital platform Meu Educativo®. Three groups were formed based on the frequency of FMS that each child mastered: group 1 (wizard level in four or five FMS); group 2 (wizard level in two or three FMS); and group 3 (wizard level in at most one skill). Multilevel models were used to analyze the data treating children (level‐1) nested within schools (level‐2).ResultsCompared to group 1, groups 2 (−12.9 ± 2.3 min day−1) and 3 (−23.9 ± 2.4 min day−1) were less physically active during weekdays and weekends (group 2: −14.7 ± 2.7 min day−1 and group 3: −22.4 ± 2.9 min day−1), independent of age and sex. There was a decline in MVPA during the weekend. Further, on average, boys were more active than girls, and with increasing age, children were less active.ConclusionOn average, children with higher FMS levels are generally more physically active than their peers with lower FMS levels. Even though MVPA tends to decline on weekends, FMS proficiency is a significant factor in maintaining 60 min of MVPA on weekends.