California's 20th State Assembly district is one of 80 California State Assembly districts.

It is represented by Democrat Liz Ortega of San Leandro.

The district is located in the southern East Bay, centered on Hayward.

The district is a major gateway between the Tri–Valley to the east, Silicon Valley to the south, and the rest of the San Francisco Bay Area.

Due to redistricting, the 20th district has been moved around different parts of the state.