Keith Roberts Porter was a Canadian-American cell biologist. Keith Porter was born in Yarmouth, Nova Scotia on June 11, 1912, the son of Aaron and Josephine Roberts Porter. Porter studied biology at Acadia University and Harvard University, from which he obtained a Ph.D. in 1938. From 1939 to 1961 he was a member of the Rockefeller Institute in New York City. 

Porter was a member of the biology department at Harvard from 1961 to 1970, serving as its chairman (1965–67). He also chaired (1968–75) the newly formed department of molecular, cellular, and developmental biology at the University of Colorado at Boulder and served for several years as part-time director of the Marine Biological Laboratory at Woods Hole, Massachusetts. The author of more than 200 scientific papers, he wrote, with Mary Bonneville, An Introduction to the Fine Structure of Cells and Tissues. Porter was elected to the U.S. National Academy of Sciences in 1964 and was the recipient of a number of prestigious awards, including the National Medal of Science (1976). He died on May 2, 1997 in Bryn Mawr, Pennsylvania, United States.