The 1974 Trans-AMA motocross series was the fifth annual international series established by the American Motorcyclist Association as a pilot event to help establish motocross in the United States. The motocross series was an invitational based on a 500cc engine displacement formula, run on American tracks featuring the top riders from the F.I.M. world championship against the top American riders. Suzuki factory rider Roger De Coster claimed the championship with four overall victories. His Suzuki teammate, Dutchman Gerrit Wolsink took second place along with one overall victory. Maico factory rider Adolf Weil claimed third place, while the top American rider was Bultaco's Jim Pomeroy in fourth place.

1974 Trans-AMA final standings

1974 Trans-AMA Round 1

Oct. 6, 1974, Unadilla, New York

1974 Trans-AMA Round 2

Oct. 13, 1974, Linnville, Ohio

1974 Trans-AMA Round 3

Oct. 20, 1974, Gainesville, Georgia

1974 Trans-AMA Round 4

Oct. 27, 1974, Orlando, Florida

1974 Trans-AMA Round 5

Nov. 10, 1974, Whitney, Texas

1974 Trans-AMA Round 6

Nov. 17, 1974, Puyallup, Washington

1974 Trans-AMA Round 7

Nov. 24, 1974, Livermore, California

1974 Trans-AMA Round 8

Dec. 1, 1974, Saddleback, California