The 1998 International Sports Racing Series was the second season of International Sportscar Racing Series (later known as the FIA Sportscar Championship). It was a series for sportscar-style prototypes broken into two classes based on power and weight, called SR1 and SR2, as well as a class of hillclimb-style sportscars, called CN. It began on April 13, 1998, and ended December 6, 1998, after 8 races.
Points are awarded to the top 10 finishers in the order of 20-15-12-10-8-6-4-3-2-1. Only the highest placing car within a team earned points towards the championship. The SportsRacing World Cup was available to all teams that participated, but separate SR2 and CN championships were also held.