So how are they marking the occasion?
Will Meghan and Harry join?
The family marked the special day by releasing a new photograph of the little Prince beaming from ear to ear.
George is the eldest child of the Duke and Duchess of Cambridge, and third in line to the throne. He is big brother to Princess Charlotte, three, and Prince Louis, two months.
The Cambridges tend to keep their children’s birthdays private family affairs.
The family of five are rumoured to be enjoying their first family summer holiday together on the island of Mustique in the Caribbean. Mustique has about 100 luxury villas and there is a no-fly zone over the area, which would be perfect for the Cambridges to enjoy some privacy while they celebrate their first born.
There have been whispers of a garden party planned for when the family gets back from holiday to celebrate the birthday with friends and family.
In that case, it is very likely Meghan and Harry will join in the fun to celebrate the little royal.
For now, however, we can only imagine George is spending his special day running around the white sand beaches of the exotic island while his parents enjoy some downtime. Read More from EXPRESS