Mitchell Nelson Weinert (born August 14, 1951 in Middletown, New York) was a pioneering motocross and supercross rider in the early years of the sport in the United States. In the 1970s he won 22 AMA Nationals and three AMA championships. In 1973, Weinert became the first American to defeat international-level riders in the Trans-AMA motocross series. That victory marked a turning point that brought American motocross up to par with the then dominant European riders.
Weinert was the son of a motorcycle dealer and began riding at an early age. Early in his career, he split his time between motocross and dirt track oval racing however, an injury while racing on the high speed dirt track ovals convinced him to concentrate on the burgeoning sport of motocross. Weinert began racing professionally in 1970 riding a CZ. In 1972 he finished runner up to Gary Jones in the AMA 250cc motocross national championship. Weinert earned a place on the Kawasaki factory racing team and went on to win the 1974 AMA 500cc national championship. He successfully defended his title in 1975. He also won the 1976 AMA 250cc Supercross championship. Injuries began to take their toll and he retired during the 1980 season.
- American Motorcyclist, January 1976, Vol. 30, No. 1, ISSN 0277-9358
- Jimmy Weinert's 1974 Kawasaki KX450 race bike at the American Motorcyclist Magazine
- Jimmy's Theme