Grand Isle is a town in Jefferson Parish in the U.S. state of Louisiana, located on a barrier island of the same name in the Gulf of Mexico. The island is at the mouth of Barataria Bay where it meets the Gulf. The town of Grand Isle is statistically part of the New Orleans−Metairie−Kenner metropolitan statistical area, though it is not connected to New Orleans' continuous urbanized area. The population was 1,005 as of the 2020 U.S. census, down from 1,296 from the previous 2010 U.S. census.