Yes — for users in the United States, Google Maps really has changed “Lake Ontario” to “Lake America.” Google confirmed the rollout on August 29 after the U.S. Geographic Names Information System was updated following President Trump’s August 27 executive order. 

But it is not a universal worldwide rename:

• U.S. users: see “Lake America.”
• Canadian users: still see “Lake Ontario.”
• Users elsewhere: Google says they will see both names. 

Reuters independently confirmed that Google Maps has implemented the change for U.S. users. Canada does not recognize the U.S. naming change, and Canadian officials have explicitly said they will continue calling it Lake Ontario. 

So the fact-check is:

✅ True: Google Maps changed the displayed name to Lake America for U.S. users.

❌ Misleading: “Lake Ontario has officially been renamed worldwide.” It has not.

Verdict: 🟢 TRUE, with a major geographic caveat.