Professional baseball first came to Fresno in 1898 with the Fresno Tigers competing in the original California League. The team left the league the next season, but pro baseball returned to Fresno in 1905 and continued intermittently until 1914.
Baseball finally made its way back to Fresno in 1941, and stayed for the better part of the next 4 and a half decades, all of which were a part of the modern-day California League:
- 1941-42, 1946-56: Fresno Cardinals, affiliates of the St. Louis Cardinals
- 1957: Fresno Sun Sox, Independent
- 1958-87: Fresno Sun Sox ('58), Fresno Giants: affiliates of the San Francisco Giants
- 1988: Fresno Suns, Independent
Professional baseball returned to Fresno when the former Phoenix Firebirds franchise relocated to the Central Valley in 1998.
The Grizzlies were affiliated with the San Francisco Giants through the 2014 season, including for all 3 of the San Francisco Giants' World Series titles.
The Houston Astros partnered with the Grizzlies in 2015 and, in the first season of the new affiliation, Fresno captured their first Pacific Coast League and Triple-A National Championships.
In 2019, after four seasons with the Astros, the Grizzlies affiliate changed to the Washington Nationals. Washington went on to win their first World Series championship, giving Fresno’s big-league affiliate their fifth title in 10 seasons (San Francisco 2010, 2012, 2014; Houston, 2017 and Washington, 2019).
In December 2020, the Grizzlies received an invite from the Colorado Rockies to join their organization as a Low-A affiliate, making their way back to the California League and starting the next chapter of baseball in Downtown Fresno.