“The 1984 Louisiana World Exposition” was held in New Orleans, Louisiana, United States, from May 12 to November 11, 1984, on the banks of the Mississippi River. Organized by Louisiana World Exposition, Inc., it was a specialized exhibition under the theme "The World of Rivers, Fresh Water as a Source of Life." It coincided with the centennial of the World's Industrial and Cotton Centennial Exposition held in New Orleans in 1884. The BIE records about 7.3 million visits.

The project had roots in efforts by Louisiana business leaders to counter economic decline and won the backing of Governor Edwin Edwards and developer Lester Kabacoff. The nonprofit Louisiana World Exposition, Inc. was formed in 1976, and the 89th General Assembly of the International Exhibitions Bureau (Bureau International des Expositions, BIE) recognized the Expo on April 22, 1981. Its organizers aimed to renew the city's urban core, promote New Orleans as a tourist destination, redevelop the riverside Warehouse District, and prepare the way for a large convention center.

The 34-hectare site offered a monorail to move crowds, a gondola that carried visitors 61 meters above the Mississippi, and the 805-meter Wonderwall, described as a "stationary Mardi Gras parade." A Neptune sculpture and a pair of mermaids greeted visitors at the main entrance. The riverfront amphitheater, designed by architect Frank Gehry, hosted performers including Willie Nelson, Linda Ronstadt and Neil Young. The official mascot, Seymore D. Fair, a white pelican in a blue tuxedo, is described by the BIE as the first Expo mascot.

The BIE lists 15 participants. The United States pavilion displayed NASA's prototype Space Shuttle Enterprise, which drew 2.6 million visits, and two 3-D cinemas screened “Water, the Source of Life,” a 20-minute film produced by Charles Guggenheim. The Italian Village became a popular place to dine, and the Japanese pavilion combined water-themed exhibits with Japanese history, culture and traditional celebrations.

Attendance fell far short of projections. Organizers needed an average of 65,000 visitors a day to break even, and the Expo filed for bankruptcy while its gates were still open. Court records cited by the Associated Press put total losses at about $121 million, and bankruptcy proceedings continued until 1993, with some creditors receiving as little as eight cents on the dollar.

The long-term effect on the city was more positive. Streets and buildings in the Warehouse District were renovated and turned to commercial and residential use, and the area grew into an arts district known for its galleries and restaurants. The Louisiana Pavilion became the Ernest N. Morial Convention Center, which opened in 1985, and a waterfront shopping center rose where the international pavilions had stood. Expo 1984 New Orleans was a financial failure that nonetheless reconnected the city with its riverfront.