Niceville is a city in Okaloosa County, Florida, United States, located near Eglin Air Force Base on Boggy Bayou that opens into Choctawhatchee Bay.The population was 11,684 at the 2000 census. The 2010 census population for Niceville was 12,749.Niceville is part of the Fort Walton Beach?Crestview?Destin Metropolitan Statistical Area.