Metairie is an unincorporated community and census-designated place in Jefferson Parish, Louisiana, United States, and is part of the New Orleans metropolitan area. With a population of 143,507 in 2020, Metairie is the largest community in Jefferson Parish, the fifth-largest CDP in the United States, and the largest outside Clark County, Nevada. It is an unincor…Metairie is an unincorporated community and census-designated place in Jefferson Parish, Louisiana, United States, and is part of the New Orleans metropolitan area. With a population of 143,507 in 2020, Metairie is the largest community in Jefferson Parish, the fifth-largest CDP in the United States, and the largest outside Clark County, Nevada. It is an unincorporated area that would have been Louisiana's fourth-largest city behind Shreveport if incorporated.