President Donald Trump signed an executive order on August 27 directing the renaming of Lake Ontario to Lake America, intensifying a growing trade dispute with Canada. The order requires the U.S. Interior Department and the U.S. Board on Geographic Names to implement the change within 30 days. Trump signed the order in the Oval Office, standing beside a map of the Great Lakes with the slogan “Making the Great Lakes Greater.”
Lake Ontario, which borders Toronto—the largest city in Canada—has historically been shared between the two countries under a 1909 treaty. Approximately 52% of the lake’s surface area lies within Canadian jurisdiction, with the remainder in New York. However, White House staff secretary Ben Moss emphasized that most of the lake’s volume, including its deepest regions, falls under U.S. territory. “This will reflect that this is an American lake,” Moss said as he presented the order to the president.
The directive instructs Interior Secretary Doug Burgum and the board to update the Geographic Names Information System and ensure all federal documents, maps, and contracts reflect the new name. The move comes amid an escalating tariff conflict after trade negotiations between the United States and Canada collapsed on August 22.
Trump accused Canadian officials of imposing “enormous tariffs” on American agricultural products and labeled them as having “treated us very badly.” Following the breakdown, the U.S. administration imposed 50% tariffs on numerous Canadian goods. Canada responded by levying tariffs ranging from 15% to 50% on U.S. exports. Trump has also threatened to increase tariffs on Canadian automobiles and auto parts from 25% to 50%.
Canadian Prime Minister Mark Carney dismissed the renaming as symbolic and declared on social media that the name Lake Ontario would remain “then, now and always.” He noted the lake’s name dates back more than 400 years, originating from the Iroquois word “Ontarí’io,” meaning “lake of shining waters.” The name first appeared on European maps in the 1660s.
The authority to name or rename geographic features in the United States lies with the U.S. Board on Geographic Names, a panel representing multiple federal agencies. Typically, name changes undergo a formal review process, but this has been expedited in recent years following President Trump’s 2025 executive order to rename the Gulf of Mexico to the Gulf of America. Despite that earlier change, the international community, including Mexico, continues to use the traditional names.
Addressing the Lake Ontario renaming, Trump drew a parallel to the previous renaming of the gulf and suggested the possibility of changing the names of the Atlantic or Pacific Oceans in the future to further reinforce American identity.