The 1990 Champion Spark Plug 400 was the 19th stock car race of the 1990 NASCAR Winston Cup Series season and the 21st iteration of the event.

The race was held on Sunday, August 19, 1990, before an audience of 60,000 in Brooklyn, Michigan, at Michigan International Speedway, a two-mile (3.2 km) moderate-banked D-shaped speedway.

It is known as a "sister track" to Texas World Speedway as MIS's oval design was a direct basis of TWS, with moderate modifications to the banking in the corners, and was used as the basis of Auto Club Speedway.

Michigan International Speedway is recognized as one of motorsports' premier facilities because of its wide racing surface and high banking (by open-wheel standards; the 18-degree banking is modest by stock car standards).

Alan Kulwicki, driving for his own AK Racing team, would win the pole, setting a time of 41.147 and an average speed of 174.982 miles per hour (281.606 km/h) in the first round.