Robert Arthur (1909-1969) was a versatile mystery writer born November 10, 1909, on Corregidor Island, where his father served as a U.S. Army officer. He is best known as the creator of The Three Investigators, a mystery book series for young people, but he began his career writing for the pulps, and later worked in both radio and television. He studied at William and Mary College for two years before earning a B.A. in English and an M.A. in Journalism from the University of Michigan. In 1931, he moved to New York City, where he wrote mysteries, fantasies, and horror stories for magazines like Weird Tales, Amazing Stories, Detective Fiction Weekly, and Black Mask throughout the 1930s.

Later, with David Kogan, he co-created and produced The Mysterious Traveler radio show (1944-1952), earning a 1953 Edgar Award. He and Kogan also won an Edgar, in 1950, for Murder By Experts. In 1959, Arthur relocated to Hollywood, scripting for The Twilight Zone and serving as story editor and writer for Alfred Hitchcock Presents, while ghost-editing numerous "Alfred Hitchcock" anthologies for adults and children.

In 1963, Arthur settled in Cape May, New Jersey, where he created The Three Investigators series with The Secret of Terror Castle (1964). He wrote ten novels in the series before his death in Philadelphia on May 2, 1969. The 43-title series, continued after his death by writers-for-hire working for Random House, was published in over twenty-five languages and thirty countries. (Originally branded as "Alfred Hitchcock and The Three Investigators", Random House dropped the Hitchcock name from the series after Hitchcock's death.)

In June of 2024, Hollow Tree Press reissued Robert Arthur's original ten novels as a sixtieth anniversary edition. Those editions have end notes written by his daughter and son-in-law, Elizabeth Arthur and Steven Bauer, and Hollow Tree Press is also publishing a twenty-six book New Three Investigators series written by Arthur and Bauer.