Chalmette is a census-designated place (CDP) in, and the parish seat of, St. Bernard Parish in southeastern Louisiana, United States. The 2010 census reported that Chalmette had 16,751 people; 2011 population was listed as 17,119; however, the pre-Katrina population was 32,069 at the 2000 census. At the 2020 U.S. census, its population rebounded to 21,562. Chalmette is part of the New Orleans–Metairie–Kenner metropolitan statistical area. Chalmette is located east of downtown New Orleans and south of Arabi, towards Lake Borgne.