Sir Robert Laird Borden was the last Canadian Prime Minister to be knighted (1914).
The Canadian titles debate has been ongoing since the adoption of the Nickle Resolution in 1919. This resolution marked the earliest attempt to establish a Canadian government policy forbidding the Sovereign from granting knighthoods, baronetcies, and peerages to Canadians, and set the precedent for later policies prohibiting Canadians from accepting or holding titles of honour from Commonwealth or foreign countries.
Its adoption and use as a precedent in the area of titular honours for Canadians is also an important part of the history of the creation of the Order of Canada in 1967, which was designed to bestow honours on those recipients whom the Government of Canada recommends that the Queen of Canada honour with membership in the Order, without endowing those recipients with titles. (from Wikipedia)