Pierre Dupuy, CC, CMG (French pronunciation: [pjɛʁ dypɥi]; July 9, 1896 – May 21, 1969) was a Canadian diplomat and writer.

In 1922 he joined the department of External Affairs, working in Paris as secretary for the office of the then Canadian Commissioner General.

During World War II, Canada, unlike Britain, did not break off its diplomatic relations with the Vichy regime in France.

On 2 November 1940, the British Foreign Secretary, Lord Halifax, asked the Canadian government to allow Dupuy to visit Vichy so as to "make an informal report on [the] present situation [there] which would be of considerable value".

Mackenzie King, the Canadian prime minister, quickly agreed "in the hope that such a visit would aid in some measure in throwing light on the present uncertainty and in establishing more friendly relations between the Government of France and the British Commonwealth".

British Prime Minister Winston Churchill noted that he was deeply grateful for Dupuy's "magnificent work", adding that "the Canadian channel is invaluable and indeed, at the moment, our only line."