The city of Gretna is the parish seat of Jefferson Parish, 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 New Orleans–Metairie–Kenner Metropolitan Statistical Area.
Gretna was settled in 1836, originally as Mechanicsham, growing with a station on the Mississippi River for the Missouri Pacific Railroad, Texas and Pacific Railway, and Southern Pacific Railroad, with a ferry across the River to New Orleans. The famous spice-maker Zatarain's was founded here in 1889. Gretna was incorporated in 1913, absorbing the section of McDonogh within the Jefferson Parish boundaries.