Robert L. Tiemann is an American baseball historian based in St. Louis, and a member of SABR (the Society of American Baseball Research). He is considered a 19th-century baseball expert. Tiemann has written or edited several baseball books, including Nineteenth Century Stars, Baseball's First Stars, Cardinal Classics: Outstanding Games from Each of the St. Louis Baseball Clubs 100 Seasons and The National Pastime: A Review of Baseball History (Volume 10). In 1992, he received SABR's Bob Davids Award, the organization's highest honor.