The UC San Diego Tritons baseball program represents the University of California San Diego at the National Collegiate Athletic Association's Division I level as a member of the Big West Conference (Big West). The Tritons have made several appearances in the Division II tournament, mostly under the leadership of former head coach Dan O'Brien. The Tritons reached the Division II College World Series for the First time in 2009, finishing fourth. In 2010, the Tritons enjoyed their most successful season to date, compiling a record of 54–8, and reaching the Division II national championship where they eventually fell.