President Donald Trump has ordered the U.S. government to stop calling Lake Ontario by its historic name and begin referring to the shared Great Lake as “Lake America.” Canada, however, is under no obligation to follow him.
Trump signed Executive Order 14420 on Thursday, August 27, 2026, directing the Interior Department and the U.S. Board on Geographic Names to update federal maps, contracts, documents and communications. The order gives officials 30 days to revise the federal Geographic Names Information System and remove its references to “Lake Ontario.”
The result is an unusual split: U.S. federal agencies will use “Lake America,” while Canada, international organizations, private mapmakers and others can continue using Lake Ontario.
What Trump’s order actually changes
The signed White House order instructs the Interior secretary to coordinate the change with the Board on Geographic Names, the federal body that standardizes place names used by the U.S. government.
Trump described the change as effective immediately while signing the order, although its written instructions allow 30 days for the federal database and related records to be updated. Federal agencies will then be expected to use the new name on official maps and documents.
The order does not transfer territory, change the international boundary or give the United States new control over the water. It changes the name used by the U.S. federal government.
Why Canada does not have to accept it
Lake Ontario is shared by the United States and Canada, bordering New York on the American side and the province of Ontario on the Canadian side. Reuters reported that approximately 52% of the lake’s surface area lies in Canada, with the remainder in New York under a 1909 treaty.
There is no single international authority that decides the names of shared bodies of water. A U.S. president has broad power over federal naming conventions, but cannot compel another country to use the same terminology.
The Associated Press reported that Canadian officials had already dismissed the proposed change. After the order was signed, Nova Scotia Premier Tim Houston wrote, “It’s Lake Ontario, buddy.” Prime Minister Mark Carney’s office had not immediately issued a response.
A name with Indigenous roots
The name Ontario predates both the modern province and the current international border. AP reported that it comes from the Huron Indigenous word oniatarí:io, commonly translated as “lake of shining waters.” The province of Ontario, established in 1867, took its name from the lake.
The White House framed its decision around American history, economic activity and investment in the Great Lakes. The order points to U.S. shipping, power generation and environmental spending, and says the deepest waters lie on the American side, giving the United States most of the lake’s volume.
The trade fight behind the new name
The renaming arrives amid a sharp deterioration in U.S.-Canada relations. Trade negotiations collapsed after three days of talks, with both governments blaming the other side.
AP reported that the United States imposed 50% tariffs on approximately $20 billion in Canadian goods and that Canada answered with tariffs on a similar amount of American steel, dairy products, appliances and agricultural equipment.
Trump said the name change was not intended to send a specific geopolitical message, but he again accused Canada of taking advantage of the United States on trade and defense. The move follows his January 2025 order directing federal agencies to use “Gulf of America” instead of “Gulf of Mexico.”
What happens next
U.S. federal databases and documents should begin reflecting “Lake America” as agencies implement the order. Whether major map services, state governments, news organizations or the public adopt the term will be decided separately.
For people standing on the Canadian shore, the lake will remain Lake Ontario. For Washington’s official paperwork, it is becoming Lake America. The water and border have not changed—only the name the U.S. government is ordering itself to use.
