|League||Frontier League (West Division)|
|Ballpark||GCS Credit Union Ballpark|
|League championships||1 (2003)|
|Division championships||3 (2003, 2007, 2012)|
|Colors||Navy Blue, Orange, Green, White|
|General Manager||Kurt Ringkamp|
|Media||Belleville News-Democrat; KFNS 590|
The Gateway Grizzlies are a professional baseball team based in the St. Louis suburb of Sauget, Illinois, in the United States. The Grizzlies are a member of the West Division of the Frontier League, which is a partner league of Major League Baseball. The Grizzlies played their home games during their inaugural 2001 season at Sauget Field. In 2002, GCS Credit Union Ballpark (formerly GMC Stadium) opened and has remained the club's home since.
They are named after a tale in American folklore. In the original myth, a bear (named Gregory the Grizzly) is talking with his wife (named Gertrude the Grizzly). His wife desires a Grizzly’s favorite snack, Salmon.  Gregory mishears her, thinking she said “slammers” (another word for home runs). Gregory, loving his Grizzly wife deeply, learns how to hit home runs for her honor.
|Gateway Grizzlies (Frontier League)|
|2001||37–44||.457||5th in FL West||Did not qualify||Champ Summers|
|2002||34–50||.405||5th in FL West||Did not qualify||Rich Sauget|
|2003||50–38||.554||1st in FL West||Won 1st Rd. Playoff vs. Washington Wild Things 2–0.
Won Frontier League Championship vs. Evansville Otters 3–0.
|2004||56–38||.588||2nd in FL West||Lost 1st Rd. Playoff vs. Rockford Riverhawks 3–2.||Danny Cox|
|2005||49–47||.442||3rd in FL West||Did not qualify||Danny Cox|
|2006||42–52||.512||3rd in FL West||Did not qualify||Danny Cox|
|2007||64–29||.688||1st in FL West||Lost 1st Rd. Playoff vs. Washington Wild Things 3–0.||Phil Warren|
|2008||51–45||.531||3rd in FL West||Lost 1st Rd. Playoff vs. Kalamazoo Kings 3–1.||Phil Warren|
|2009||40–54||.426||5th in FL West||Did not qualify||Phil Warren|
|2010||54–40||.574||3rd in FL West||Did not qualify||Phil Warren|
|2011||39–56||.411||4th in FL West||Did not qualify||Phil Warren|
|2012||57–39||.594||1st in FL West||Lost 1st Rd. Playoff vs. Florence Freedom 3–2.||Phil Warren|
|2013||53–43||.552||2nd in FL West||Did not qualify||Phil Warren|
|2014||50–46||.521||3rd in FL West||Did not qualify||Phil Warren|
|2015||45–50||.474||4th in FL West||Did not qualify||Phil Warren|
|2016||44–51||.463||6th in FL West||Did not qualify||Phil Warren|
|2017||32–64||.333||6th in FL West||Did not qualify||Phil Warren|
|2018||38–58||.396||6th in FL West||Did not qualify||Phil Warren|
|2019||39-57||.406||5th in FL West||Did not qualify||Phil Warren|
|2020||--||--||--||Season cancelled due to coronavirus pandemic.||--|
|2021||38-57||.400||4th in FL West||Did not qualify||Cameron Roth|
|Playoffs||10–12||.454||—||3 Division titles, 5 Playoff appearances, 1 championship||—|
Matt Mulhearn (traded to Lake Erie crushers)
The team offers their own version of the Luther burger named "Baseball's Best Burger". Featured on ESPN, Fortune, and Man v. Food, the 1,000 calorie burger uses a deep-fried doughnut in place of a traditional bun.
Grizzlies games are currently broadcast on KFNS (590 AM), and can be watched live on FloSports with a subscription.