Long Beach is a city located in Harrison County, Mississippi, USA. It is part of the GulfportBiloxi, Mississippi Metropolitan Statistical Area. According to the United States Census Bureau, before Hurricane Katrina, the city had a total area of 10.3 square miles (27 square kilometer). 10.1 square miles (26 square kilometer) of it was land and 0.2 square miles (0.52 square kilometer) of it was water. The total area was 1.85% water.