John Jacob Quinn (April 1, 1908 – September 20, 1976) was an American executive in Major League Baseball. His career spanned over 40 years and included almost 28 full seasons as a general manager in the National League for the Boston and Milwaukee Braves and Philadelphia Phillies. He produced three National League pennants and one World Series championship during his 1945–58 tenure with the Braves.
Quinn was a member of one of the game's most prominent multi-generational families. During the era between the end of World War I and the end of World War II, his father, J. A. Robert Quinn, held various senior management and ownership positions in baseball: business manager of the St. Louis Browns, general manager of the Brooklyn Dodgers, and owner/general manager of both the Boston Red Sox and Boston Braves. John J. Quinn's son, son-in-law and grandson have also been senior baseball executives.
Quinn was born in Columbus, Ohio, during the period when his father was the president and business manager of the minor league Columbus Senators.
A graduate of Boston College, Quinn worked with his father in the Red Sox front office, then rejoined J. A. Robert Quinn with Boston's National League franchise from 1936–45, serving as club treasurer and, later, farm system director. He succeeded his father as the Braves' general manager in 1945, working under the club's new ownership group headed by Lou Perini. He served in the GM post through the 1958 season, from the Braves' final seven years in Boston through their highly successful first six years as the Milwaukee Braves, winning the 1948 National League pennant in Boston, and the 1957 World Series and 1958 NL title in Milwaukee.