William Harold Fishman (March 2, 1914 – January 25, 2001) was a Canadian-American cancer researcher who taught at Tufts University from 1948 until his retirement in 1975. In 1976, with a $180,000 grant from the National Cancer Institute, he co-founded the La Jolla Cancer Research Foundation (since renamed the Sanford Burnham Prebys Medical Discovery Institute) with his wife, Lillian. He was also the founding editor-in-chief of Tumor Biology, serving in this role from 1980 to 1983.