Robert L. Fish, the youngest of three children, was born on August 21, 1912, in Cleveland, Ohio. He attended the local schools in Cleveland and went to Case University (now Case Western Reserve), from which he graduated with a degree in mechanical engineering. He married Mamie Kates, also from Cleveland, and together they have two daughters. Fish worked as a civil engineer, traveling and moving throughout the United States. In 1953 he was asked to set up a plastics factory in Rio de Janeiro, Brazil. He and his family moved to Brazil, where they remained for nine years. He played golf and bridge in the little spare time he had. One rainy weekend in the late 1950s, when the weather prohibited him from playing golf, he sat down and wrote a short story that he submitted to Ellery Queen's Mystery Magazine. When the story was accepted, Fish continued to write short stories. In 1962 he returned to the United States; he took one year to write full time and then returned to engineering and writing. His first novel, The Fugitive, won an Edgar Award for Best First Mystery. When his health prevented him from pursuing both careers, Fish retired from engineering and spent his time writing. His published works include more than forty books and countless short stories. Mute Witness was made into a movie starring Steve McQueen.

Fish died February 23, 1981, at his home in Connecticut. Each year at the annual Mystery Writers of America dinner, a memorial award is presented in his name for the best first short story. This is a fitting tribute, as Fish was always eager to assist young writers with their craft.