Sam Epstein (November 22, 1909 - January 31, 2000) was an American author of juvenile non-fiction books.
Starting in 1938, Sam, along with his wife Beryl Williams Epstein, jointly wrote over 120 books.

Although Sam is often individually credited for many of the books, Beryl played a major role in their creation. While Epstein and his wife had very different writing styles, they took turns writing chapters and editing each other’s work, enabling their styles to blend together.
The couple contributed numerous titles to several children’s book series, including the Real Books, All About, and Franklin Watts First Book series.

They also wrote the Ken Holt Mystery series under the name Bruce Campbell.