The president pro tempore of the California State Senate is the highest-ranking leader and most powerful member of the California State Senate. The officeholder also chairs the Senate Rules Committee. At the beginning of each two-year session, all members of the body elect a new State Senate President pro tempore. The President pro tempore is chosen by the other Senators.

The California State Senate is the upper house of the California State Legislature, the lower house being the California State Assembly. The state senate convenes, along with the state assembly, at the California State Capitol in Sacramento.