A graduate of Westborough High in Massachusetts, Jack Butterfield enrolled at the University of Maine and became a two-sport standout in football and baseball in the early 1950s. He then coached football, basketball and baseball at Foxcroft Academy for two years (the '54 baseball team won the state title with a 32-1 record) before returning to the University of Maine.
Initially coaching three sports, Butterfield eventually settled in as the head baseball coach and an assistant with the Black Bears' football team.
Butterfield's coaching career began at Maine in 1956, when he assisted head coach Walter Anderson and coached the school's junior varsity team. For the 1957 season, Butterfield was named the head coach. He held the position from 1957–1974 and compiled an overall record of 240-169-2 (.584).
Maine's best season under Butterfield was 1964, when the team went 21-8 and won the Yankee Conference outright to qualify for the program's first NCAA Tournament. In the best-of-three District 1 Regional held in Boston, Maine swept Northeastern in two games to advance to the College World Series. There, Maine won its opening game against Seton Hall, 5-1, before dropping its second to Minnesota, 12-0. In the loser's bracket, the Black Bears defeated Arizona State and USC but were eliminated by Missouri and finished third. Butterfield was named NCAA Coach of the Year.
In Butterfield's 17 seasons at Maine, the team won eight Maine State Series (a competition between Maine, Bowdoin, Colby, and Bates) and shared three other Yankee Conference titles but did not qualify for another NCAA Tournament.
Butterfield's players at Maine included Major Leaguers John Cumberland and Bert Roberge, college head coach Jack Leggett, baseball executive Bill Livesey, and New York Yankees manager Carl "Stump" Merrill.
Following the 1974 season, Butterfield left Maine to become the head coach at South Florida, where he led the bulls for two seasons (1975–1976) and had an overall record of 61-24-1.
Butterfield's No. 21 jersey was retired by the University of Maine, and he was inducted into the Maine Sports Hall of Fame in 2009.
