California's 27th senatorial district is one of 40 California State Senate districts.

It is currently represented by Democrat Henry Stern of Malibu.

The district straddles the Los Angeles–Ventura county border and encompasses most of Los Angeles's western suburbs.

The district includes the Conejo Valley, parts of the San Fernando Valley, and a slice of the Santa Clarita Valley.

Los Angeles County – 6.3% Ventura County – 38.7%