Frederic Dannay was an American author, best known for co-creating the fictional detective Ellery Queen with his cousin, Manfred B. Lee. Born on March 20, 1905, in New York City, Dannay was a significant figure in the mystery genre, contributing to both novels and short stories featuring the clever sleuth. The duo's work often involved intricate plots and puzzles, engaging readers in solving the mysteries alongside the protagonist. In addition to his writing, Dannay was influential in the literary community, serving as an editor and critic. He played a key role in establishing the Ellery Queen Mystery Magazine, which showcased various mystery writers and helped popularize the genre. His contributions have left a lasting impact on detective fiction.