Jason Derik Isringhausen
- Bats Right, Throws Right
- Height 6' 3", Weight 195 lb.
- School Lewis and Clark Community College
- High School Southwestern High School (Piasa)
- Debut July 17, 1995
- Final Game September 19, 2012
- Born September 7, 1972 in Brighton, IL USA
Jason Isringhausen was drafted in the 44th round of the 1991 amateur draft. Though not typically associated with great major league prospects, the 44th round of that draft was the birthplace of three very steady playing major leaguers in Jason Isringhausen, Damian Jackson and Bobby Jones.
Isringhausen was a member of the New York Mets' highly touted, but ultimately disappointing, "Generation K", with Paul Wilson and Bill Pulsipher. Isringhausen struggled as a starter with the Mets before being traded to the Oakland Athletics with Greg McMichael for reliever Billy Taylor in 1999. With Oakland he found success as a closer. As a free agent he moved on to the St. Louis Cardinals in 2002, helping the Cardinals to the 2004 World Series. In 2004, Isringhausen tied Lee Smith's Cardinals team record for saves in a season with 47, while leading the National League in that category. Isringhausen went on to win a World Series ring with the Cardinals in 2006, despite not playing in the postseason due to injury. Young Adam Wainwright replaced him as closer for the push to the title.
After struggling in 2008 Isringhausen went on to pitch for the Tampa Bay Rays in 2009. Injuries limited him to only 19 games, with only 9 of those coming at the big league level. After pitching for the Cincinnati Reds AAA team, the Louisville Riverbats, in 2010 Isringhausen returned to the Mets for the 2011 season. Working out of the bullpen he put up a 4.05 ERA in 53 games while picking up 7 saves. In 2012, Isringhausen ended his career pitching for the Los Angeles Angels of Anaheim, putting up a similar mark of 4.14 ERA in 50 games. After the season he retired and joined the coaching staff of Southern Illinois University Edwardsville.
- 1995 Pitcher of the Year International League Norfolk Tides
- 2-time All-Star (2000 & 2005)
- NL Saves Leader (2004)
- 30 Saves Seasons: 7 (2000-2002 & 2004-2007)
- 40 Saves Seasons: 1 (2004)
- Won a World Series with the St. Louis Cardinals in 2006 (he did not play in the World Series)
- Adrian Garro: "The Hall of Fame Case: Jason Isringhausen", "Cut4", mlb.com, January 4, 2018. 
- Joe Posnanski: "Isringhausen, Lidge rejuvenated careers in 'pen: Pair of closers on Hall of Fame ballot for first time", mlb.com, December 27, 2017.