Niceville is a city in Okaloosa County, Florida, United States, located near Eglin Air Force Base on Boggy Bayou that opens into Choctawhatch…Niceville is a city in Okaloosa County, Florida, United States, located near Eglin Air Force Base on Boggy Bayou that opens into Choctawhatchee Bay. It is part of the Crestview–Fort Walton Beach–Destin, Florida Metropolitan Statistical Area. The population was 15,772 at the 2020 census, up from 12,749 at the 2010 census.