John O'Neil was a professional baseball player who played as a catcher for various teams during his career. He was born on February 23, 1926, in Hartford, Connecticut, and began his baseball career in the minor leagues in 1946.

O'Neil played for several minor league teams before making his major league debut with the Milwaukee Braves in 1953. He played for the Braves for two seasons before being traded to the Philadelphia Phillies in 1955. O'Neil played for the Phillies for two seasons before being traded to the Chicago Cubs in 1957.

O'Neil played for the Cubs for three seasons before being traded to the St. Louis Cardinals in 1960. He played for the Cardinals for two seasons before being traded to the Pittsburgh Pirates in 1962. O'Neil played for the Pirates for one season before being traded to the Houston Colt .45s (now the Houston Astros) in 1963.

O'Neil played for the Colt .45s for one season before being traded to the New York Mets in 1964. He played for the Mets for one season before being traded to the Baltimore Orioles in 1965. O'Neil played for the Orioles for one season before being traded to the California Angels in 1966.

O'Neil played for the Angels for one season before being traded to the Washington Senators in 1967. He played for the Senators for one season before being traded back to the Angels in 1968. O'Neil played for the Angels for one season before being traded to the Seattle Pilots (now the Milwaukee Brewers) in 1969.

O'Neil played for the Pilots for one season before retiring from baseball. Throughout his career, O'Neil was known for his strong defensive skills as a catcher. He was also known for his ability to handle pitchers and call a good game.

After retiring from baseball, O'Neil worked as a scout for several teams, including the Milwaukee Brewers, the San Diego Padres, and the Kansas City Royals. He was also a coach for the Royals for several years.

In 2008, O'Neil was inducted into the Professional Baseball Scouts Hall of Fame. He passed away on January 22, 2013, at the age of 86.