Trump announced the change on Thursday from the Oval Office. He said the new name would take effect immediately.
However, the order applies only to US federal references. It does not control what Canada, international organizations or other groups call the lake.
The decision quickly drew criticism from Canadian and US officials. Canadian Prime Minister Mark Carney said the lake’s historic name would remain unchanged.
New York Governor Kathy Hochul also rejected the new name. New York shares the US side of Lake Ontario with Canada.
Canada rejects new lake name
Carney pointed out that Lake Ontario’s name dates back more than 400 years. He said the lake existed before Canada and the United States became modern nations.
He argued that Canadians would continue to call it Lake Ontario.
About 52% of the lake’s surface lies in Canada. The remaining portion is within New York State.
The name itself comes from the Wendat language. Grand Chief Pierre Picard of the Wendat Nation in Quebec criticized Trump’s decision and said it threatened to erase part of the region’s history.
Vermont Governor Phil Scott also described the move as petty and disappointing.
Name change adds to trade tensions
The controversy comes as US-Canada trade relations remain under pressure.
Trade talks between Washington and Ottawa collapsed last week after three days of negotiations. Both sides blamed the other for the breakdown.
The two countries are also dealing with tariffs affecting billions of dollars in cross-border trade.
Canadian officials have raised several concerns during negotiations. These include proposed changes affecting French-language rules, tariff relief for trucks and Canada’s ability to establish new trade agreements.
Against that backdrop, the lake name change is unlikely to improve relations.
Trump jokes about renaming oceans
Trump went further on Thursday by suggesting that he could consider renaming major oceans.
He joked that after changing the name of a gulf and a lake, the next step could involve the Atlantic or Pacific oceans.
The comments added to the controversy surrounding the Lake Ontario decision.
Trump has also repeatedly spoken about Canada becoming the 51st US state. Canadian leaders have firmly rejected that idea.
For now, Lake Ontario remains the name used by Canada and much of the international community. Trump’s order changes how the lake is referenced by the US federal government, but it does not give Washington control over the lake’s internationally recognized name.
The dispute has therefore become another symbol of the broader political and economic tensions between the United States and Canada.
