Biloxi is a city in Harrison County, Mississippi, United States. It lies on the Gulf Coast in southern Mississippi thirteen miles east of Gulfport along US-90. The adjacent cities are both designated as seats of Harrison County. The population of Biloxi was 49,449 at the 2020 census, making it the state's 4th most populous city. It is a principal city of the Gulfport–Biloxi metropolitan area, home to 416,259 residents in 2020. The area's first European settlers were French colonists.