Kelly was a first team All-American goalie of the U.S. Intercollegiate Lacrosse Association in 1936 and 1937, his junior and senior years at the University of Maryland. The Terps lost only one collegiate game during the three years that Kelly was guarding the Maryland goal. Maryland was undefeated in collegiate competition in 1936-1937, in 1936 winning the W. Wilson Wingate Trophy, symbolic of lacrosse supremacy and sharing the trophy with Princeton in 1937.
Kelly's first introduction to lacrosse was at Boys' Latin School in Baltimore, where he was a member of the 1932 Maryland Scholastic Association champions. Kelly was an All-Maryland Prep selection as goalie.Loyola College, after an absence from lacrosse circles for approximately ten years, resumed collegiate lacrosse in 1938 and Kelly was named head lacrosse coach. He coached at Loyola until the end of 1941, when he resigned because of World War II. His Greyhounds, who never had a losing season, won 65 percent of all their games.
Kelly was named editor of the Lacrosse Coaches Association Newsletter in 1951. He changed the name of the publication to the Lacrosse Newsletter in 1954 and continued to edit and publish the newsletter through 1974. In addition to editing the Lacrosse Newsletter, Kelly also promoted lacrosse by encouraging editors of other sports publications to give greater coverage to lacrosse.
His contacts among the college coaches enabled a number of high school lacrosse players to receive financial help in college. His promotion work was also responsible for at least two colleges recognizing lacrosse as a varsity sport. His advice and assistance to students at the University of Notre Dame in helping to establish lacrosse on a club basis led to the setting up of the Notre Dame John F. Kelly Trophy, which is awarded to the winner of the Notre Dame Invitational Lacrosse Tournament. Several sports writers considered the Newsletter their lacrosse bible.
Jack Kelly served as Chairman of the USILA Publicity Committee from 1954 to 1966. He had been a member of the Board of Directors of the Lacrosse Foundation, Inc., after it was established. In 1958 he received the USILA award for his contribution to lacrosse during the year.
Jack Kelly passed away in 1998.