John Sadler may refer to:
John Leonard Sadler (born 19 November 1981, Dewsbury, Yorkshire, England) is an English first-class cricketer, representing Derbyshire. He has previously played for several major teams in the English league including Leicestershire, Yorkshire Cricket Board and Yorkshire. His current position is Head Coach of Glasshoughton Cricket Club.
Sadler missed most of the 2005 season through injury, after a Brett Lee bouncer broke his collar bone.
In July, 2013 it was announced that Sadler had taken up a part-time coaching job with the University of York Cricket Club (UYCC).
John Sadler is a British historian specialising in the Anglo-Scottish Border conflicts during the Middle Ages. Sadler is a regular contributor to military and historical journals and has published a number of books on the subject. He has taught and tutored history as well.