Florence Green served with the Women’s RAF (WRAF) in 1918 and although she did not see front-line action, the charity Veteran’s Aid said she qualifies as a veteran of the war.
Mrs Green, who turns 109 next month and is a great-grandmother-of-seven, worked as a waitress in the officers' mess during the war at RAF Marham and Narborough Airfield, both in Norfolk.
Her story came to light after Andrew Holmes, a British correspondent for the United States-based Gerontology Research Group, traced her name using the National Archive.
Mrs Green, who was born on February 19, 1901 and joined the WRAF aged 17, said she had been unaware of her status until very recently.
Before the discovery of Mrs Green's service history, it was believed that British-born Gladys Powers, who died in Canada in 2008, was the last female veteran.
ZUI also this article from the King's Lynn (Norfolk) Lynn News.
[T]housands of women ... "did their bit" between 1914 and 1918 - and Mrs Green has survived them all.
After enlisting in 1918, she recalls working in the officers' mess at Marham and was also based at Narborough airfield. She said: "I enjoyed it. There were plenty of people there and they were very good company. It was lovely."
Unaware of her special status until now, she said: "I am proud."
Mrs Green was born in London but Lynn has been her home for about 90 years. She lives with her daughter, May, and has two other children, June, who lives in Oundle, and Bob, who lives in Cumbria. She has four grandchildren and seven great-grandchildren.
The three other confirmed WWI veterans still alive in January were John Babcock (Canadian Expeditionary Force), Frank Buckles (US Army) and Claude Choules (Royal Navy). Douglas Terrey, of England, claims to have served in the British Army Ordnance Corps in 1917, but no official records of his service have been located.