The Big West was founded in 1969 as the Pacific Coast Athletic Association. It adopted the name Big West in 1988.
CSU Bakersfield and UC San Diego both joined in 2020, giving the conference its current membership.
The Big West Conference is composed of 11 schools, and all 11 currently field a baseball team. Of its member schools, seven are in Southern California (indicated in boldface).
Following the 2026-2027 academic year, UCSD will be moving to the West Coast Conference, while the Big West will welcome Cal Baptist and Utah Valley University, currently in the Western Athletic Conference, and Sacramento State University from the Big Sky Conference (although the Hornets currently play baseball as an affiliate member of the WAC).
- Cal Poly SLO
- Cal State Bakersfield
- Cal State Fullerton
- Cal State Northridge
- Long Beach State
- UC Davis
- UC Irvine
- UC Riverside
- UC San Diego
- UC Santa Barbara
- University of Hawaii