Bill Gallagher debuted on May 2, 1883, playing for the Baltimore Orioles at Oriole Park; he played his final game on June 18, 1884, playing for the Philadelphia Keystones at .
John Gallagher debuted on August 20, 1915, playing for the Baltimore Terrapins at ; he played his final game on October 3, 1915, playing for the Baltimore Terrapins at .
Bill Gallagher played in 9 games at outfield for the Baltimore Orioles in 1883, starting in none of them. He made 12 putouts, had 2 assists, and committed 3 errors, equivalent to .333 errors per game (estimate based on total games played in). He had one double play.
Bob Gallagher debuted on May 17, 1972, playing for the at ; he played his final game on September 26, 1975, playing for the New York Mets at Shea Stadium.
Dave Gallagher debuted on April 12, 1987, playing for the Cleveland Indians at Cleveland Stadium; he played his final game on October 2, 1995, playing for the California Angels at Anaheim Stadium.
Doug Gallagher debuted on April 9, 1962, playing for the Detroit Tigers at Tiger Stadium; he played his final game on September 26, 1962, playing for the Detroit Tigers at Tiger Stadium.
Gil Gallagher debuted on September 13, 1922, playing for the Boston Braves at Braves Field; he played his final game on October 1, 1922, playing for the Boston Braves at Braves Field.
Sean Gallagher debuted on June 9, 2007, playing for the Chicago Cubs at Wrigley Field; he played his final game on October 3, 2010, playing for the Pittsburgh Pirates at PNC Park.
Shorty Gallagher debuted on August 13, 1901, playing for the Cleveland Blues at League Park I; he played his final game on August 13, 1901, playing for the Cleveland Blues at League Park I.
William Gallagher debuted on August 19, 1896, playing for the Philadelphia Phillies at Baker Bowl; he played his final game on September 1, 1896, playing for the Philadelphia Phillies at Baker Bowl.
Al Gallagher debuted on April 7, 1970, playing for the San Francisco Giants at Candlestick Park; he played his final game on September 27, 1973, playing for the California Angels at Anaheim Stadium.
Joe Gallagher debuted on April 20, 1939, playing for the New York Yankees at Yankee Stadium I; he played his final game on September 29, 1940, playing for the Brooklyn Dodgers at Ebbets Field.
Ed Gallagher debuted on July 8, 1932, playing for the Boston Red Sox at Fenway Park I; he played his final game on September 24, 1932, playing for the Boston Red Sox at Fenway Park I.