The 2004 Oceania Swimming Championships were held May 15–19, 2004 at the National Aquatics Center in Suva, Fiji. This was the fifth edition of the Championships, and featured competitions in: swimming, open water swimming and synchronized swimming (synchro). The synchro competition marked the first time the sport had been swum in Fiji. All swimming competition listed below were swum in a 50m (long-course) pool.