15Shem Davies - 29 (Young)
Shem Davies became a grandfather at the shocking age of 29 when his 14-year-old daughter gave birth to a baby girl in 2011. Davies was also young when he gave birth to his daughter at just 14 with his then-girlfriend who was 15. He became Britain’s youngest granddad at the
time. He told The Daily Mail, "It is an absolute joy to see Gracie thriving. I'm incredibly proud of Tia. She'll be a brilliant mum. At first I wasn't overly pleased that she was pregnant but I soon got over that. Now, it's all about being positive." Hopefully, his granddaughter doesn't also follow suit, which would possibly make Shem Britain's youngest great-grandfather.