Picayune is the largest city in Pearl River County, Mississippi, United States. The population was 11,885 at the 2020 census. The city is located approximately 45 miles (72 km) from New Orleans, Hattiesburg, and Gulfport–Biloxi. The Stennis Space Center is 10 miles (16 km) away. Picayune is part of the New Orleans–Metairie–Hammond combined statistical area.