The fuddle duddle incident in Canadian political history occurred on February 16, 1971, when Prime Minister of Canada Pierre Trudeau was alleged to have spoken or at least mouthed unparliamentary language in the House of Commons, causing a minor scandal. Trudeau mentioned the words "fuddle duddle" in an ambiguous answer to questions about what he may or may not have said in Parliament.

In February 1971, opposition MPs accused Trudeau of having mouthed the words "fuck off" at them in the House of Commons. When pressed by television reporters on the matter, Trudeau would only freely admit having moved his lips, answering the question, "What were you thinking, when you moved your lips?" by rhetorically asking in return "What is the nature of your thoughts, gentlemen, when you say 'fuddle duddle' or something like that? God, you guys!" Thus, it remained unclear what Trudeau actually mouthed.

In a 2015 speech, his son, and later Prime Minister, Justin Trudeau stated that his father "didn't actually just say 'fuddle duddle'".