The boundary of the Simcoe Muskoka District Health Unit covers 8,800 square kilometers of land area. According to the 2016 Census, 540,249 people, or 61 people per square kilometer, were living in the service area of the Simcoe Muskoka District Health Unit. This included 479,650 living in Simcoe County and 60,599 living in the District of Muskoka.
The City of Barrie, with a population of 141,434 people, was the municipality with the largest population in Simcoe County. In the District of Muskoka, Huntsville had the largest population, with 19,816 residents.
