Beverly Atlee Cleary was an American writer of children's and young adult fiction. One of America's most successful authors, 91 million copies of her books have been sold worldwide since her first book was published in 1950. Some of her best known characters are Ramona Quimby and Beezus Quimby, Henry Huggins and his dog Ribsy, and Ralph S. Mouse.

Ralph S. Mouse is the third in a children's novel trilogy that was written by Beverly Cleary. It features Ralph, a mouse with the ability to speak, but only with certain people who tend to be loners. It was first published in 1982, illustrated by Paul O. Zelinsky.