Physical activity has numerous mental, emotional, spiritual and physical benefits. The factors influencing physical activity among First Nations children have not been well studied. The objective was to examine the associations between several intrapersonal, family and community factors and physical activity among First Nations school-aged children residing in First Nations communities. Participants consisted of 3,184 children (6-11 years old) from the 2008/10 First Nations Regional Health Survey, a representative sample of First Nations persons who reside in on-reserve and northern First Nations communities. The survey addresses a holistic range of health issues. Primary caregivers completed interviews to assess each child's moderate-to-vigorous physical activity (MVPA), participation in traditional physical activities, six intrapersonal factors, four family factors and two community factors. Based on primary caregiver reports, 72% of children accumulated a daily average of ≥60 minutes of MVPA and 54% participated in at least one traditional First Nations physical activity in the past year. Older age, having more people in the household, and having more relatives help the child understand their culture were independently associated with accumulating ≥60 minutes of MVPA. School attendance, use of First Nations language, having parents with a high school education, smaller community size, and having more community members help the child understand their culture were independently associated with participation in traditional First Nations physical activities. Among First Nations children, there are several correlates of physical activity from diverse ecological levels.