Matt O'Neill Stats & Bio | Diamondbacks Catcher

About Matt O'Neill

Matt O'Neill is a catcher for the Arizona Diamondbacks, wearing jersey number 66 and bringing a steady presence behind the plate. Standing 5'11" and weighing 205 pounds, O'Neill combines athleticism with the mental sharpness required at one of baseball's most demanding positions. Born on August 20, 1997, in Morristown, New Jersey, he developed his passion for the game in the competitive baseball landscape of the Northeast. O'Neill honed his skills at the University of Pennsylvania, where his intelligence and work ethic set him apart as a serious professional prospect. His academic background at an Ivy League institution reflects the cerebral approach he brings to reading pitchers and managing a game from behind the dish. O'Neill continues to represent both his New Jersey roots and the Diamondbacks organization with professionalism and dedication.

Updated: Mar 6, 2026