California's 42nd State Assembly district is one of 80 California State Assembly districts. It is currently represented by Democrat Jacqui Irwin.
Before redistricting in 2022, the district straddled the gateway between the Inland Empire and the California desert, stretching from Yucaipa and Hemet in the west to the Twentynine Palms region and western Coachella Valley in the east. It now covers the western suburbs of Los Angeles and eastern part of Ventura County, including Calabasas, Malibu, the Conejo Valley, Moorpark, and Simi Valley.
Due to redistricting, the 42nd district has been moved around different parts of the state. The current iteration resulted from the 2021 redistricting by the California Citizens Redistricting Commission.