The San Joaquin County Registrar of Voters Office is a division of the County Administrator's office and is responsible for conducting fair, impartial, accurate, secure and transparent federal, state and local elections. Other functions of the Registrar of Voters Office include voter registration, election administration and campaign finance disclosures.

As of September 7, 2021, San Joaquin County has 380,294 Active registered voters of an estimated population of 432,516 eligible voters. It takes about 900 staff members, poll workers and election night workers to conduct a countywide election.