John Thorn is a leading baseball historian and author/editor/publisher of hundreds of sports books. Apart from his creation, with Pete Palmer, of Total Baseball, he is often visible on ESPN, The History Channel, This Week in Baseball, and other television outlets as a baseball authority and commentator. He was also a major on-screen presence in and chief consultant to Ken Burns's 18½-hour PBS film, Baseball.

With Palmer, Thorn wrote The Hidden Game of Baseball, which established alternative statistics later recognized and adopted as official by Major League Baseball. His baseball books include Treasures of the Baseball Hall of Fame, The Game for All America, Our Game, and The Whole Baseball Catalogue. With Michael Gershman and a legion of writers, he worked with Microsoft programmers to create the definitive sports multimedia product, Complete Baseball. He has written for children (Baseball's Ten Greatest Games, among others) and has launched children's publishing programs for Major League Baseball and the Baseball Hall of Fame.

Thorn lives in Kingston, New York. He has three sons, Jed (27), Isaac (22), and Mark (16), as well as grandson Bryce.