Canada imposes high tariffs on dairy products imported from the US, including milk and butter, through a supply management system. For milk, the initial tariff is 7.5% for USMCA signatories, but this can increase to 241% once a specific import quota is exceeded 3 4. While the exact tariff rate for butter is not specified in the search results, it is subject to similar supply management policies as milk, which dictate higher tariffs once initial quotas are surpassed 3 4.

President Donald Trump has frequently cited a 250% or 270% tariff on US dairy exports to Canada 1 2. However, it's important to note that these high tariffs only apply after certain import quotas are met, as part of Canada's supply management regulations 3 4. These measures are permitted under the USMCA trade agreement.

Despite these high tariffs, US dairy exports to Canada have been growing, reaching $1.14 billion in 2024, nearly doubling over a decade 4.