John Whipple Dwinelle (September 9, 1816 – January 28, 1881) was an American lawyer and politician. He served in a number of political posts in California and played important roles in both the legal history of San Francisco and the establishment of the California public university system. While trying to catch a ferry, Dwinelle fell from a pier in Port Costa, California, and drowned. His body washed ashore three weeks later.