In times of national crisis, brave men and women across America nobly sacrifice their occupations and home life to defend their country in the U.S. military. Historically, baseball players have been no different. Hundreds of ballplayers have enlisted during their major league careers, many of them bypassing some of their prime seasons on the diamond. Others, like Hall of Fame pitcher Christy Mathewson, joined the armed forces after their playing days had come to an end.
The following lists consist of Hall of Fame members who have defended America during times of war. The lists are sorted by military conflicts.