Diamondhead is a city in southeastern Hancock County, Mississippi, United States. The city is located just over 50 miles northeast of New Orleans, Louisiana. It is part of the Gulfport?Biloxi Metropolitan Statistical Area. In February 2012, Diamondhead was officially incorporated as a city. At the time of the 2010 census, when Diamondhead was an unincorporated census-designated place, the population was 8,425. The city population, with slightly different boundaries, was estimated at 8,217 in 2016.