Watch: Trump signs executive order renaming Lake Ontario to Lake America
US President Donald Trump has signed an executive order seeking to rename Lake Ontario to Lake America.
The move comes after trade talks between the US and Canada collapsed late last week, and the US imposed new 50% tariffs on $20bn (C$28bn) worth of Canadian goods. Canada will implement "dollar for dollar" counter tariffs next month.
Trump has repeatedly posted threats about renaming the lake, one of the five Great Lakes that straddle both countries, on social media amid the trade dispute.
He said on Thursday the move was "official, effective immediately" and that his administration has "filed all the necessary papers, documents" to make the change.
Canadian Prime Minister Mark Carney noted the name Lake Ontario can be traced back more than 400 years, noting in a social media post on Thursday that preceded the formation of the Canadian Confederation and the US Declaration of Independence.
"We know that the United States is changing. Their trade relations, their foreign policy, their national monuments, their hydronyms," he wrote. "Canadian women and men also know that things must be called by their name, and this lake is called Lake Ontario – today and forever."
When Trump took the White House in 2025, he signed a similar order that changed the Gulf of Mexico to the Gulf of America. Mexico has rejected the name change, arguing a single country cannot rename a shared body of international water.
It also led to a dispute between Mexico and tech giant Google, which renamed the gulf in its maps application. , external
In that case, Google Maps users in the US see "Gulf of America", while those in Mexico see the "Gulf of Mexico". Those in other countries see the "Gulf of Mexico (Gulf of America)".
There is no universally recognized international body setting the names of international waters. While the US president has broad discretion over how his country officially recognises landmarks, other countries do not have to follow.
Trump's latest order directs the US Department of the Interior to update the Geographic Names Information Service – the official repository of domestic geographic names in the US – to reflect the name change, the president said.
Canada, however, does not have to recognise name changes made by other countries and officials dismissed the idea in remarks earlier this week.
"We'll always call it Lake Ontario," said Industry Minister Melanie Joly on Tuesday.
The names of four of the Great Lakes – Ontario, Huron, Michigan and Erie – originate from indigenous words. Lake Superior was named after an anglicised French word. Lake Ontario, the smallest of the Great Lakes, borders both the Canadian province and the US state of New York.
