"This is about everyday Canadians standing up for the country," Ontario Premier Doug Ford said of the accessory.

The leader of Canada’s most populous province on Wednesday countered Donald Trump’s tariff threats to the northern nation by using a medium that the U.S. president-elect’s base knows well: hats.

Doug Ford, the premier of Ontario, rocked a navy blue “Canada Is Not For Sale” hat with a Canadian flag patch during a press conference — a not-so-subtle jab at Trump’s red “Make America ...