Dunnellon is a city in Marion County, Florida, United States. The population was 1,928 at the 2020 census, up from 1,733 in 2010. It is part of the Ocala Metropolitan Statistical Area. Dunnellon was founded in 1887, two years before the 1889 discovery of phosphate in the area. It was officially incorporated as a city in 1891. The subsequent mining boom, the first of its kind in Florida, lasted until the early 1910s. The original mining took place in and around the Rainbow River using the river's natural flow to transport phosphates. One of the original mining pits is now called the 'Blue Cove' subdivision. Phosphate industry operations began to shift south to the Polk County area, and by the 1960s, Dunnellon's last mine closed. Dunnellon survived the bust period, unlike other nearby phosphate towns including Romeo, LeRoy, Brewster, and Parkersburg.