The 1998 Australian Super Touring Championship was the sixth running of a CAMS sanctioned motor racing series in Australia under the Super Touring Car regulations and the fourth to carry the Australian Super Touring Championship name. It began on 5 April 1998 at Calder Park Raceway and ended on 30 August at Oran Park Raceway after eight rounds. The series was promoted by TOCA Australia as the 1998 BOC Gases Australian Super Touring Championship. As in the British Touring Car Championship the race format changed with each meeting now consisting a shorter "sprint" race and a "feature" race, 25% longer than previous races featuring a mandatory two-tyre stop to be taken between 15 and 75% distance. The one exception was the round at Lakeside Raceway where the pit lane was deemed unsuitable.
Independents Cup points were awarded on a 15-12-10-8-6-5-4-3-2-1 basis for relative positions achieved by drivers in entries nominated as Independents at each race.
The TOCA Challenge - Independents Cup was won by Cameron McLean in his Greenfield Mowers Racing-entered BMW 320i, scoring 205 points. Second was Mark Adderton on 151 points, and third was Peter Hills on 136 points.