Why Is Lake Ontario Also Being Called Lake America?

Lake Ontario is one of the five Great Lakes of North America. It lies between the Canadian province of Ontario and the US state of New York. For centuries, it has been known in English as Lake Ontario. In August 2026, however, the United States government gave it a second name: Lake America.

On August 27, 2026, President Donald Trump signed an executive order directing US federal agencies to use the name Lake America. The order took effect immediately within the US federal government, and the new name was added to the US Geographic Names Information System.

The change was made during a period of worsening relations between the United States and Canada. Trump presented it as recognition of the United States’ role in protecting and developing the Great Lakes. The executive order mentions American investments, shipping, icebreaking and the fact that the deepest parts of the lake are on the US side.

Canada does not accept the new name. Canadian Prime Minister Mark Carney and the government of Ontario have said that the lake will continue to be called Lake Ontario in Canada. The United States cannot officially rename the entire lake because it is shared by two countries. The executive order only determines which name is used by the US federal government.

This means that both names may now appear on maps. Google Maps shows Lake America to users in the United States, Lake Ontario to users in Canada, and both names to many users elsewhere. Other map services may make different choices. As a result, two people looking at the same lake online may see different names depending on where they are located.

The name Ontario is much older than either the United States or Canada. It comes from an Indigenous language and is generally interpreted as meaning “sparkling water” or “great body of water.” The lake gave its name to the Canadian province of Ontario when Canada was formed in 1867.

This is not the first time the Trump administration has changed the American name of a major geographical feature. In 2025, it renamed the Gulf of Mexico the Gulf of America for official US use and restored the name Mount McKinley for the mountain also widely known as Denali.

For geography students, Lake Ontario remains the internationally familiar name. Lake America is now its official name within the US federal government. Which name appears on a particular map depends on the country, the map publisher and the naming rules it follows.