Clarence Roderic Allen (February 15, 1925 – January 21, 2021) was an American geologist who studied seismology.

He was a graduate of Reed College (B.A., 1949) and the California Institute of Technology (M.S., 1951; Ph.D., 1954).^[1]

Allen was President of the Seismological Society of America in 1975^[2] and the Geological Society of America. He was a member of the American Association for the Advancement of Science, the American Geophysical Union, and the Geological Society of America. He was elected a Fellow of the American Academy of Arts and Sciences in 1975.^[3] Allen was a member of the National Academy of Sciences and the National Academy of Engineering since 1976.^[4]

Allen received the first G.K. Gilbert Award in Seismic Geology and in 1995 he received the Medal of the Seismological Society of America.^[5]

He was a member of the faculty of the California Institute of Technology since 1955.^[6] He became a Professor Emeritus there in 1990.^[1]

Allan died on January 21, 2021, at the age of 95.^[7]

• "Geology of Earthquakes" with Robert S. Yeats and Kerry E. Sieh. Oxford University Press (1997) ISBN 0-19-507827-6
• "Comparative study of the neotectonics of the Xianshuihe fault, China" (1987)
• "Continuation of creep and strain studies in southern California" (1984)
• "Creep and strain studies in southern California: Final technical report" (1986)
• "Seismicity of the Southern California Region, 1 January 1932 to 31 December 1972" with John M. Nordquist and James A. Hileman (1973)
• "Active faulting in northern Turkey" (1969)
• "Agua Blanca fault: A major transverse structure of northern Baja California, Mexico" (1960)