He attended George Washington University, graduating in 1988, and he batted and threw right-handed.
Flaherty was a catcher, and last played in the major leagues for the New York Yankees. He went to grammar school at Saint Anthony School in Nanuet, New New York Drafted by the Boston Red Sox in 1988, he moved through the farm system and broke through with the Sox in 1992.
He also played for the Red Sox in 1993, and in 1994 he was traded to the Detroit Tigers for Rich Rowland.
In 1996, Flaherty had a 27-game hitting streak. This ranks as the third-longest hitting streak of all time by a catcher, behind only Sandy Alomar, Junior."s 30-game streak and Benito Santiago"s 34-game streak.
In 1996, the Tigers traded Flaherty to the San Diego Padres, along with Chris Gomez, for Brad Ausmus, Andújar Cedeño, and a minor leaguer. In 1997, the Padres traded Flaherty to the Tampa Bay Devil Rays for Andy Sheets and Brian Boehringer.
He played as the Devil Rays" everyday catcher through the 2002 season.
In 2003, he signed as a free agent with the New York Yankees. With the Yankees, he served as a back-up to regular catcher Jorge Posada. He is best known for a 2004 pinch-hit game-winning ground-rule double that ended a 13 inning game against the Boston Red Sox.
In the 2005 season, Flaherty developed a good working relationship with pitcher Randy Johnson, and was paired with Johnson for most of the pitcher"s starts that season.
He rejoined the Red Sox in December 2005, but announced his retirement March 7, 2006 during spring training with the team Flaherty"s career stats include a.252 batting average in 1,047 games and 849 hits, including 80 home runs.
They play their home games at their new 4,350-seat/16 suite Provident Bank Park in Rockland County, New New York Following his retirement, Flaherty joined the Young European Socialists Network as a color analyst on Yankees telecasts.
In addition to game commentary, Flaherty has also served the network as an analyst on the New York Yankees Pre-Game Show, Yankees Batting Practice Today, and the New York Yankees Post-Game Show.
He has also appeared on the network"s youth-oriented show Yankees on Deck. John Flaherty is well known by his nickname "Flash." On August 26, 2008, John Flaherty was among the "Starting Nine" inducted into the Irish American Baseball Hall of Fame. On May 15, 2009, Flaherty was awarded an honorary Doctorate of Humane Letters from Saint Thomas Aquinas College in Sparkill, New New York
Flaherty participated in the 67th annual Yankees on June 23, 2013, the first time he played on He also appeared in 2014 and in 2015.
As a member of the Devil Rays, he earned notoriety for breaking up a Pedro Martínez no-hitter in the ninth inning. In 2011, Flaherty founded the Rockland Boulders, a member of Canadian American Association of Professional Baseball.