Answer box
Lake America and Lake Ontario are the same lake. There is no second body of water and nothing about the shoreline, depth or international boundary changed in 2026. What differs is the label: U.S. federal systems say Lake America, Canada says Lake Ontario, and consumer map apps pick one based on where the user is.
Side by side
| What | Lake America | Lake Ontario |
|---|---|---|
| Body of water | The easternmost Great Lake | The same easternmost Great Lake |
| U.S. federal label | Lake America, since Aug. 27, 2026 | Historic label, retained in some pre-existing titles |
| Canadian label | Not recognized | Lake Ontario, unchanged |
| Google Maps | Shown to users in the United States | Shown to users in Canada; both names shown elsewhere |
| Apple Maps | Shown to users in the United States | Shown to users in Canada |
| MapQuest | MapQuest said it would not adopt the rename | MapQuest said it would keep Lake Ontario |
| Geography | About 193 miles long, roughly 7,340 square miles | Identical — no shoreline, depth or border changed |
What should travellers call it?
Whichever name the person you are talking to uses. On the Canadian shore, in ferry timetables and on provincial signage, it is Lake Ontario. On U.S. federal pages and on a U.S. phone, you will see Lake America. Both will be understood on either shore, and no border crossing, booking or road sign depends on which you say.
For search and navigation, the practical note is that the pin does not move. Typing either name into a map app lands you in the same water.