Is the oxygen sensor functional on a Canadian Apple Watch?

If you have brought a Watch from Canada to the US, the first time that you update the watchOS in the States, the Oxygen sensing function will most likely be disabled. watchOS updates are country-specific.

M1 Mac mini, macOS 15.3.1;  Watch, series 10 GPS-only, watchOS 11.3.1; iPhone 16, iOS 18.3.1; TV 4th Gen, tvOS 18.3; HomePods, audioOS 18.3 and Airport Express w/ Airplay 2

Interesting question. The U.S. Apple Watch has a unique model number, and that is supposedly the trigger that tells the software to disable the oxygen sensor.

And a U.S. Apple Watch taken out of the U.S. and upgraded, does not have its oxygen sensor enabled, because the model number does not change.

If you decide to do this, report back after you do your first watchOS software update inside the U.S.