Charles Almon Dewey (September 11, 1877 – March 2, 1958) was a United States federal judge in Iowa's southern district for over thirty years.
Born in Washington, Iowa, Dewey attended Oberlin College in Ohio. He was a Corporal in the U.S. Volunteers during the Spanish–American War. In 1901, he received an LL.B. from State University of Iowa, and entered private practice in Washington, Iowa. He was a City attorney of Washington from 1905 to 1909, and County attorney for Washington County, Iowa from 1909 to 1915. From 1918 to 1928, he served as a state district court judge in Iowa's sixth judicial district.
In 1927, a backlog of unresolved cases had developed in the United States District Court for the Southern District of Iowa. On January 19, 1928, President Calvin Coolidge signed into law a bill that authorized the appointment of a second judge to the Southern District of Iowa, with the proviso that when the existing judgeship becomes vacant, it shall not be filled unless authorized by Congress. On January 23, 1928, President Coolidge nominated Dewey to this new seat. He was confirmed by the United States Senate on January 31, 1928, and received his commission the same day. After over twenty years of active service, he assumed senior status on March 1, 1949. As a senior judge, he was given temporary assignments three times, sitting by designation in St. Louis, New York, and Miami. Dewey held senior status until he died in Des Moines, Iowa, on March 2, 1958.