Canada's dairy supply management system has become a flashpoint in trade tensions with the US, after Donald Trump named it as one of three grievances behind a 50% tariff on $20bn of Canadian goods, due to take effect in August. Canadian leaders, including Quebec Premier Christine Fréchette and Trade Minister Dominic LeBlanc, have signalled the system is non-negotiable, setting up a standoff between Ottawa and Washington that could complicate wider trade talks and leave the tariffs in place.

The supply management system, in place since the early 1970s, uses production quotas and provincially set prices to guarantee farmers stable incomes, while steep tariffs of 200–300% apply to imports beyond small quota limits, leaving US producers with tariff-free access to just 3.5% of the Canadian market despite $1.3bn in dairy sales there in 2025. Record US dairy output has pushed American farmers to seek greater access north of the border, and a White House order this week accused Canada of "discrimination" for giving EU cheesemakers easier access than the US under its trade deal with Europe. The policy has also drawn past criticism from the Biden administration, the UK (which walked away from trade talks over it in 2024) and the OECD, though it remains fiercely defended by Canada's politically influential dairy lobby.