The adorable five-year-old was enjoying an outing with his grandmother Carole and sister Charlotte near the Middleton family home in Berkshire when he approached a passing dog walker.
Speaking to The Sun, the woman said royal handlers asked her not to photograph the children but the eldest son of the Duke and Duchess of Cambridge came over to pet her dog.
'Just to be friendly I engaged in a bit of small talk and I asked George what his name was, even though obviously I knew it,' she said.
But to her amazement, the young prince proudly replied: 'I'm called Archie.'
The revelation has prompted speculation among fan watchers as to what the Cambridge's call their little ones in private.
The British royal family are known for bestowing multiple monikers on their children and third in line to the throne George is no exception.
His middle names are Alexander and Louis, while parents William and Kate have also created a number of adorable pet names for their first child over the last five years.
During Kate's pregnancy, the couple reportedly referred to the unborn Prince as 'our little grape'.
At school George is known as PG, a nickname which coined his parents' term of endearment 'PG Tips' or just 'Tips' after the British tea.
The story of George's latest alternative title remains uncertain, but according to She Know the name Archie is short for the Scottish 'Archibald' which means true, brave and noble.