James Edward "Sunny Jim" Fitzsimmons (July 23, 1874 – March 11, 1966) was a Thoroughbred racehorse trainer.

Born in Sheepshead Bay, Brooklyn in 1874, Fitzsimmons began his career in 1885 working at a racetrack as a stable boy.^[1] After nearly ten less-than-successful years as a thoroughbred jockey, he became too heavy for that job and took up the training of horses. He went on to have one of the most successful careers in racing history, spanning seventy years from 1894 to 1963 with 2,275 race wins.

Known as both "Sunny Jim" and as "Mr. Fitz", he trained three Kentucky Derby winners, four Preakness Stakes winners, and six Belmont Stakes winners. Included were two U.S. Triple Crown champions: Gallant Fox in 1930 and his son Omaha in 1935. Fitzsimmons' total of thirteen Classic wins was broken by D. Wayne Lukas in 2013. Five times, Fitzsimmons was the season's top money-winning trainer.

In 1923, Fitzsimmons took over training at Belair Stud. Following the death of William Woodward, Jr., Belair's owner, in 1955 and the dispersal of its stock, Fitzsimmons continued to train for the Wheatley Stable, where he conditioned Preakness winner and 1957 American Horse of the Year Bold Ruler, who sired Secretariat.

In recognition of his accomplishments, in 1958 Fitzsimmons was inducted in the National Museum of Racing and Hall of Fame.^[2]

The National Turf Writers Association created an award in his name called the "Mr. Fitz Award" to honor a member of the horse racing fraternity each year.

Sunny Jim Fitzsimmons died in 1966 in Miami. He is buried in the Holy Cross Cemetery, Brooklyn.

Selected other major stakes race wins:

• Saratoga Cup: 10
• Dwyer Stakes: 9
• Lawrence Realization: 8
• Alabama Stakes: 8
• Suburban Handicap: 5
• Withers Stakes: 4