John Francis "Jack" Shelley (September 3, 1905 – September 1, 1974) was a U.S. politician. He served as the 35th mayor of San Francisco, from 1964 to 1968, the first Democrat elected to the office in 50 years, and the first in an unbroken line of Democratic mayors that lasts to the present (as of 2014).Shelley earned a law degree from the University of San Francisco in 1932.