The 2004–05 New Orleans Hornets season was the franchise's third season in the National Basketball Association. The Hornets moved from the Eastern Conference's Central Division to the tougher Southwest Division of the Western Conference for the season. In their first losing season since the 1991–92 season, the Hornets finished the year with a franchise-worst record of 18 wins and 64 losses. They failed to qualify for the playoffs for the first time since the 1998–99 season, when the franchise was based in Charlotte.

During the offseason, the Hornets made many transactions. On June 16, the Hornets claimed Brazilian swingman Alex Garcia on waivers from the San Antonio Spurs. On June 22, the 2004 NBA Expansion Draft took place, and the Hornets lost guard Maurice Carter to the Charlotte Bobcats. Two days later, the NBA Draft took place.

In the draft, the Hornets drafted J. R. Smith and Tim Pickett. Smith would play only two seasons with the Hornets, and Pickett would not play in the NBA. On July 19, the Hornets signed Chris Andersen. Andersen would be with the Hornets for four seasons, missing the 2006–07 season due to a suspension for substance abuse. On August 3, the Hornets signed former Sixth Man of the Year Rodney Rogers. Rogers would be traded to the Philadelphia 76ers, along with Jamal Mashburn, on February 24 for Glenn Robinson. On September 29, the Hornets signed Tremaine Fowlkes and Britton Johnsen. The following day, the team signed Lorinza "Junior" Harrington and Lee Nailon. On October 28, the Hornets waived Fowlkes, and three days later, they waived Johnsen.