Fact Check: Was Lake Ontario named after Canadian province of Ontario?

WASHINGTON, DC: President Donald Trump’s recent decision to rename Lake Ontario “Lake America” has sparked debate online about the history behind the lake’s name. As social media users discuss the origins of “Ontario” and its connection to the Canadian province, a claim has circulated that Lake Ontario was named after the province.

Claim: Lake Ontario named after the province of Ontario

In late August 2026, US President Trump ordered that Lake Ontario, the easternmost of the Great Lakes, be renamed “Lake America” in US government publications.

He signed the order amid tensions with Canadian leaders over failed trade negotiations.

After the announcement, some people on social media claimed that Trump was not actually targeting a Canadian name because “Ontario” originally referred to the lake.

Several social media posts have sparked debate over the origins of Lake Ontario’s name. One user wrote, "Is someone gonna tell Trump that the lake wasn't named after the province of Ontario?" One Instagram user also reported, "You might assume Lake Ontario was named after the Canadian province. "

Fact Check: Lake Ontario was not named after the Canadian province

The claim that Lake Ontario was named after the province of Ontario is false.

Historical records show that indigenous peoples used the name “Ontario” for the lake centuries before the Canadian province adopted it. European explorers later included “Ontario” on maps of the lake.

One social media post claimed, “I was given my name by the Iroquois Nation many hundreds of years ago. By 1660, my name was printed on maps by the Europeans as they accepted the Native name, which means Beautiful waters. In 1867 the Canadian government decided to use my name for their province.”

Historical maps support this timeline. They show “Ontario” being used for the lake long before the province adopted the name in 1867. The evidence indicates that the province took the name from the lake, not the other way around.

How did Lake Ontario get its name?

The National Museum of the Great Lakes says the name “Ontario” comes from the Huron, also known as the Wendat, word “Ontarí'io,” meaning “great lake” or “beautiful water.” The word originally referred to a body of water rather than a plot of land.

According to the Canadian Encyclopedia, Europeans first used “Ontario” for the lake in 1641. The name also appeared on maps of North America as early as 1656. Maps from 1653 and 1656 used names such as Lake St Louis and Lake Ontario for the lake. A 1656 map listed Ontario first, while a 1657 map called it Ontario Lake.

These early maps did not use “Ontario” to describe the land north of the lake, which is now the province of Ontario. Even maps from 1775 and 1777 referred to the body of water as Lake Ontario.