Cal. Civ. Proc. Code § 416.50

(a) A summons may be served on a public entity by delivering a copy of the summons and of the complaint to the clerk, secretary, president, presiding officer, or other head of its governing body.
(b) As used in this section, “public entity” includes the state and any office, department, division, bureau, board, commission, or agency of the state, the Regents of the University of California, a county, city, district, public authority, public agency, and any other political subdivision or public corporation in this state.