Biloxi is a city in Harrison County, Mississippi, in the United States. The 2000 census recorded the population as 50,644, although the 2008 Census Estimate placed the population at 45,670. Along with Gulfport, Biloxi is a county seat of Harrison County.The city is part of the Gulfport-Biloxi metropolitan area and the Gulfport-Biloxi-Pascagoula, Mississippi Combined Statistical Area. Pre-Katrina, Biloxi was the third largest city in Mississippi; but with its population losses following that storm, Hattiesburg now has that distinction.The beachfront of Biloxi lies directly on the Mississippi Sound, with barrier islands scattered off the coast and into the Gulf of Mexico.Keesler Air Force Base lies within the city and is home to the 81st Training Wing and the 403rd Reserve Wing of the U.S. Air Force.