Belle Chasse is an unincorporated community and census-designated place in Plaquemines Parish, Louisiana, United States, on the west bank of the Mississippi River. Belle Chasse is part of the Greater New Orleans metropolitan area. The population was 10,579 at the 2020 United States census. Belle Chasse is the largest community in Plaquemines Paris…Belle Chasse is an unincorporated community and census-designated place in Plaquemines Parish, Louisiana, United States, on the west bank of the Mississippi River. Belle Chasse is part of the Greater New Orleans metropolitan area. The population was 10,579 at the 2020 United States census. Belle Chasse is the largest community in Plaquemines Parish. It is home to Naval Air Station Joint Reserve Base New Orleans, a Naval Air Station for the U.S. Navy Reserve.