The city of Gretna is the parish seat of Jefferson Parish, in the US state of Louisiana. Gretna is on the west bank of the Mississippi River, just east and across the river from uptown New Orleans. It is part of the Greater New Orleans Metropolitan area. The population was 17,423 at the 2000 census. Also see: Gretna Heritage Festival. Gretna apartments for rent comparison page shows most up to date rent information on Gretna apartments and houses. Rent information is obtained from multiple rental sources but we cannot guarantee their accuracy.