George Harmon Coxe was born on April 23, 1901, in Olean, New York, the son of George H. Coxe and Harriet C. Coxe. After attending public schools in Olean and the Free Academy in nearby Elmira, Coxe spent the academic year of 1919-1920 at Purdue University in West Lafayette, Indiana. The following year, he attended Cornell University in Ithaca, New York. Coxe left Cornell without finishing and drifted into a variety of odd jobs, including work in a lumber camp and later on an automobile assembly line. During this period he also wrote two stories, which he sold to Detective Story Magazine.
Moving west in 1922, Coxe became a journalist for the Santa Monica Outlook and later joined the Los Angeles Express. Moving back to New York, Coxe worked for the Utica Observer-Dispatch, the New York Commercial and Financial Chronicle, and the Elmira Star-Gazette. In 1927, Coxe left newspaper work and wrote and sold advertising for Barta Press, an agency in Cambridge, Massachusetts. In 1929, he married Elizabeth Fowler.
In 1932 Coxe gave up advertising and became a full-time writer, turning out crime and detective stories for Black Mask and other pulp magazines. From 1932 until the publication of his first crime novel in 1935, he published more than fifty detective stories. From 1935 to 1976, he published sixty-three crime novels, twenty-one of them featuring the exploits of photographer Kent Murdock. From 1936 to 1938 (and briefly in 1944-1945), Coxe worked in Hollywood as a screenwriter. He shared screen credit for Arsène Lupin Returns (1938) and for The Hidden Eye (1946), for which he had written the original story.
During World War II, Coxe wrote scripts for a radio series, The Commandos, and an audition script for Casey, Crime Photographer, a radio drama based on the Flashgun Casey stories. In 1945, he served as a special war correspondent in the Pacific theater. After the war, Coxe expanded his interests, writing stories on subjects other than detective fiction for more sophisticated magazines such as Collier’s and The Saturday Evening Post. In 1952, Coxe was elected president of the Mystery Writers of America, and in 1964 he received the organization’s Grand Masters Award. Largely inactive after the late 1970’s, he died on January 30, 1984.