Mariko Yamada (born October 23, 1950) is a Japanese-American social worker who served as the Democratic assemblywoman from California's 4th Assembly district from 2008 to 2014.

[citation needed] Prior to serving in the Assembly, Yamada represented the city of Davis on the Yolo County Board of Supervisors from 2003-2008.

She was elected in 2008 after defeating West Sacramento Mayor Christopher Cabaldon in a competitive Democratic primary, a victory that many considered an upset for Yamada.

[2] She was the third consecutive woman from Davis to be elected to this seat, following in the footsteps of Helen Thomson and Lois Wolk.

In 2016, Yamada lost the election for the seat representing California's 3rd State Senate district to Bill Dodd.