The most prominent championship in stock car racing is the NASCAR championship, currently called the Nextel Cup after its sponsor (formerly known as Winston Cup after a previous sponsor). It is the most popular racing series in the United States, drawing over 6 million spectators in 1997, an average live audience of over 190,000 people for each race.

The most famous event in the series is undoubtedly the Daytona 500, an annual 500-mile race at Daytona Beach, Florida. The series' second-biggest event is probably The Brickyard 400, an annual 400-mile race held at the Indianapolis Motor Speedway, the legendary home of the Indianapolis 500 of the Indy Racing League, an open-wheeled racing series.

NASCAR also runs the Busch Series, a stock car junior league, and the Craftsman Truck Series, a junior league where pickup trucks are raced. Together the two car-based series (Nextel Cup and Busch Series) drew 8 million spectators in 1997, compared to 4 million for both American open-wheel series (CART and IRL).

In 2002, 17 of the 20 US top sporting events in terms of attendance were NASCAR races. Only football drew more television viewers that year.