Carolyn Keene is the pseudonym used by the authors of the Nancy Drew mystery stories and The Dana Girls mystery stories, both produced by the Stratemeyer Syndicate. Additionally, the Keene pen name is credited with the Nancy Drew spin-off, River Heights, and the Nancy Drew Notebooks.

The founder of the Syndicate, Edward Stratemeyer, hired various writers to create the manuscripts for the Nancy Drew books, starting with Mildred Wirt (later Mildred Benson). These writers were paid $125 per book, relinquishing all rights to the work and maintaining confidentiality as per their contracts.

Mildred Benson is recognized as the primary writer of the Nancy Drew books under the pseudonym Carolyn Keene. Harriet Adams, Stratemeyer's daughter, later revised the original books and added new ones following Benson's departure.

Other ghostwriters who contributed to the Nancy Drew series under this pseudonym include Leslie McFarlane, James Duncan Lawrence, Walter Karig, Nancy Axelrad, Patricia Doll, Charles S. Strong, Alma Sasse, Wilhelmina Rankin, George Waller Jr., Margaret Fischer, and Susan Wittig Albert. Harriet Stratemeyer Adams's daughters were also involved, offering input on the series and sometimes assisting in selecting book titles, alongside Harriet Otis Smith, the Syndicate's secretary, who invented the characters of Nancy's friends Bess and George, and the editors at Grosset & Dunlap.

In 1979, the Stratemeyer Syndicate switched publishers to Simon & Schuster, a move contested by their former publishers, Grosset & Dunlap, in court over breach of contract. The court ruled in favor of the Syndicate, allowing them the freedom to choose their preferred publisher for future series entries.

In 1985, Simon & Schuster acquired the Syndicate, with the Drew books now managed by Mega-Books, a New York book packager.