John Albert Lynn (born March 18, 1943) is a military historian who has written on a wide variety of topics in his field, with an emphasis on early modern Europe.

Born in Glenview, Illinois, in 1943, he received his Bachelor of Arts degree at the University of Illinois at Urbana-Champaign (1964), his Master of Arts degree at the University of California, Davis (1967), and his Ph.D. at UCLA (1973).

In 2012, he returned to the University of Illinois to teach part-time as Professor Emeritus of History and in the Department of Political Science, which he has continued to do up to the present.

In 2017, he received the Samuel Eliot Morison Prize from the Society for Military History.

In August 2017, Lynn was awarded a NEH Public Scholar Grant to fund research and writing on his current project, a history of surrender.