John Dewan (born in 1954) is a baseball researcher whose work has been dedicated to bringing statistical information to the public. He was one of the founders of "Project Scoresheet" in the early 1980s, which was meant to compile and make public play-by-play accounts of all major league baseball games. Such accounts were very difficult to come by at the time, as only boxscores were published, and even those were rarely compiled in a manner that made their consultation simple. The project eventually led to Retrosheet.
Dewan later founded two companies, "STATS Inc." and "Baseball Info Solutions" that provide advanced statistics to teams, researchers and others, breaking the monopoly once enjoyed by the Elias Sports Bureau. He has been particularly important in pioneering advance defensive statistics and has edited the Fielding Bible, a compendium of this data.
He was honored with the Henry Chadwick Award in 2016.