According to this story Florence Green, the last surviving WWI veteran, has passed away at the age of 110.
She (that's not a typo, it was a female!) served in the Royal Air Force of Great Britain. It seems there is no consensus on whether anymore are alive or not. I recall a few months back there was a story announcing the last WWI veteran passed away. Regardless, it's amazing that somebody who served in any capacity in WWI (1914-1918) could still be alive today! Thank you for your service, and Rest in Peace Mrs. Green!