The 2004 Supersport World Championship was the sixth Supersport World Championship season—the eight taking into account the two held under the name of Supersport World Series. The season started on 29 February at Valencia and finished on 3 October at Magny-Cours after 10 races.
The riders' championship was won by Karl Muggeridge and the manufacturers' championship was won by Honda. Karl Muggeridge won a total of 7 races, a new record for the class.
Bold – Pole position
Italics – Fastest lap