Voters in the 20 even-numbered districts of the California State Senate elected their representatives.

[8] The 10th district is located in the southern coastal East Bay and parts of Silicon Valley, including Hayward and Milpitas.

It takes in heavily Latino portions of Fresno and Bakersfield, along with Delano, Hanford, and Porterville.

The incumbent was Republican minority Senate leader Jean Fuller, who was term-limited and could not run for reelection.

The 18th district consists of the eastern San Fernando Valley, including parts of Burbank, as well as the Los Angeles neighborhoods of Northridge, Sherman Oaks, and Van Nuys.

[1] The 22nd district is located in the southern coastal encompasses the San Gabriel Valley and parts of the foothills.

The incumbent was Democratic State Senate President pro tempore Kevin de León, who was term-limited and could not run for reelection.

[1] The 28th district is located in eastern Riverside County, including Cathedral City, Murrieta, Palm Springs, and Temecula.

[1] The 32nd district takes in the Gateway Cities region in southeastern Los Angeles County, as well as Buena Park.

The incumbent was Democrat Tony Mendoza, who was elected with 52.3% of the vote in 2014,[1] resigned following sexual assault allegations.

[25] Note that the primary was held the same day as the special election to fill a vacancy in the seat.

[26] The 34th district is centered around western Orange County, including parts of Anaheim, as well as Garden Grove and Santa Ana.