On June 28, 2018, California Gov. Jerry Brown signed into law the California Consumer Privacy Act of 2018 (AB 375).
AB 375 will go into effect on Jan. 1, 2020, unless changed in the interim.
While it has been compared with GDPR in news articles, there are significant differences.
https://datamatters.sidley.com/california-enacts-broad-privacy-protections-modeled-on-gdpr/