The 1968 Beltsville 300 was a NASCAR Grand National Series (now Sprint Cup Series) event that was held on May 17, 1968 at Beltsville Speedway in Beltsville, Maryland. The transition to purposely-built racers occurred gradually begain in the early 1960s. Changes made to the sport by the late 1960s brought an end to the "strictly stock" vehicles of the 1950s; most of the cars were trailered to events or hauled in by trucks.