Mildred Wirt Benson (July 10, 1905, to May 28, 2002), writing as Carolyn Keene, was the author of 23 of the first 30 Nancy Drew mysteries.

Benson was born Mildred Augustine in Ladora, Iowa, and was married to Asa Wirt and, after Wirt's death, to George Benson, editor of the Toledo Blade. She was a graduate in journalism from the University of Iowa. She worked for 58 years as a journalist and was still writing a weekly column for the Toledo Blade at 96 at the time of her death.

Though the books in the Nancy Drew mysteries have sold over 200 million copies worldwide, neither Benson nor her estate have ever received any royalties; she was paid a flat fee of $125 to $250 for each book.

Under the terms of her contract, Benson agreed never to reveal her role in writing the mysteries. However, in 1980 her testimony in a court case involving the publisher compelled her to reveal her identity as a Nancy Drew mysteries author. With that, Benson was able to solve, for the public at least, the final Nancy Drew mystery.

Benson's favorite Nancy Drew story was The Hidden Staircase.