Cheery Peggy Poole weighed two and a half pounds when she was born in 1918 and doctors didn't think she would survive.
But 4ft tall Peggy went on to live through the Second World War, 19 Prime Ministers and two coronations to reach triple figures.
She celebrated her big day surrounded by friends, family and even the town mayor at her home in Scarborough.
Peggy said: "I was Scarborough's smallest baby and they said I wasn't going to live but look at me now.
"I had a very good nurse who always used to take me out for a walk in the pram.
Peggy grew up in the same town just down the road with her parents and two sisters, Edna and Muriel.
Some of her fondest memories are of dancing the night away at a local dance hall, where she met her future husband Les.
Peggy said: "Me and my sister used to go to the dance hall on a Friday night when it was children's night. I had a really good time.
"At 10 o'clock my father was outside waiting and we had to go home.
"There were four of us, two boys and two girls, and the boys always walked us home and our dad was always behind them.
"It was very old-fashioned."
Peggy and Les never had children because of concerns it could have affected Peggy's health due to her small stature.
In the late 1950s the couple moved to Lepton, near Huddersfield, West Yorks, where Peggy worked at a firework shop.
Over the years the couple also spent time living in Bournemouth, Dorset, before moving back to Scarborough.
Peggy said: "I've had a very good life with lots of lovely memories."
Scarborough care company Coastal Carers visit Peggy five times a day to help her with everyday errands.
Anna Cybart, one of her carers, said: "We all love Peggy. She's very independent and she never complains.
"It's a pleasure to spend time with her. We wish her a very happy birthday."