The Missing Chums is the fourth volume in the original The Hardy Boys series of mystery books for children and teens published by Grosset & Dunlap. The book ranks 108th on Publishers Weekly's All-Time Bestselling Children's Book List for the United States, with 1,189,973 copies sold as of 2001. This book is one of the "Original 10", generally considered to be the best examples of the Hardy Boys, and Stratemeyer Syndicate, writing.