Clarence James Goodnight (May 30, 1914 – August 9, 1987) was an American zoologist who made contributions to the study of freshwater annelids and harvestmen (Opiliones).
Goodnight was born in Gillespie, Illinois.
He earned an associate degree at Blackburn College, then earned his bachelor's, master's, and PhD at the University of Illinois.
He served as president of the American Microscopical Society (1971), secretary of the American Society of Zoologists, and secretary of the North American Benthological Society.
[1][2] In 1940 he married Marie Louise Ostendorf (1916–1998), with whom he co-authored many publications and described over 300 species,[3] including more than 120 species of Mexican harvestmen.