William Clark Denison (June 1, 1928 – April 8, 2005) was an American mycologist.
Born in Rochester, New York, Denison attended Oberlin College, from which he earned a B.A.
Under the supervision of Richard Korf, Denison completed a PhD from Cornell University in 1956 on the ascomycete genus Scutellinia.
He accepted a position as associate professor in the department of botany and plant pathology at Oregon State University in 1966, simultaneously becoming curator of the mycological herbarium.
[1] He was described as "a pioneer in the use of lichens to monitor air quality in the United States".