Francis Patrick Duffy was a Canadian American soldier, Catholic priest and military chaplain.
Duffy served as chaplain for the 69th Infantry Regiment, a unit of the New York Army National Guard largely drawn from the city's Irish-American and immigrant population. He served in the Spanish–American War, but it is his service on the Western Front in France during World War I for which he is best known. Duffy, who typically was involved in combat and accompanied litter bearers into the thick of battle to recover wounded soldiers, became the most highly decorated cleric in the history of the United States Army.
Duffy Square – the northern half of New York City's Times Square between 45th and 47th Streets – is named in his honor.