James Otis Kaler (March 19, 1848 — December 11, 1912) was an American journalist and author of children’s literature, primarily in the boys' adventure genre. The vast majority of his works were published under the name James Otis, but he also wrote as Amy Prentice, Harry Prentice, and Lt. James K. Orton. His works include the Boy Spies series, the Navy Boys series, the Minute Boys series, a number of historical novels published by the American Book Company, and more than thirty novels about life in New York State.