There was no incumbent; the office was vacant due to the previous Lieutenant Governor, Frank Merriam, becoming governor on June 2, 1934 after the death of James Rolph.
Source for Popular Vote data: California Secretary of State. Statement of Vote at General Election Held on Nov. 6, 1934 in the State of California, California Secretary of State (https://archive.org/details/statementofvote192639cali/page/n593/mode/2up?view=theater) (accessed 14 Dec 2023)