Kenneth Frank Baker (June 3, 1908–April 16, 1996) was an American phytopathologist (plant disease researcher). In his early career he held a number of positions with the United States Forest Service and United States Department of Agriculture. Following a three-year period in Hawaii researching pineapple pathogens, he accepted a position at the University of California, Los Angeles, where he remained for twenty-one years. He was elected as a fellow of the American Association for the Advancement of Science in 1950 and as a fellow of the American Phytopathological Society in 1969. Additionally, he served as the editor of the Annual Review of Phytopathology for five years.