The 1998 Mosport Festival was a multi-class sports car and GT motor race held at Mosport International Raceway in Bowmanville, Ontario, Canada on August 9, 1998. It was the fifth round of the 1998 Professional SportsCar Racing Championship season. The race was held over a two-hour-and-45-minute time period, during which 128 laps of the 3.9-kilometre circuit were completed for a race distance of 506.544 kilometres.