The future king will have just returned from his latest official royal tour with his family through Poland and Germany, adding to the list of global locations he's already visited in his short time on the planet.
Prince George in particular looked both cranky and miserable during his public appearances as he clearly looked like he wanted to be anywhere else but with his parents on their trip.
I'm thrilled and honoured that the Duke and Duchess of Cambridge have chosen to release this portrait to celebrate Prince George's fourth birthday.
To mark his fourth birthday, a new image of Prince George has been released by his parents, Prince William and Duchess Kate of Cambridge.
George's parents, the palace added, "are very pleased to share this lovely picture, and would like to thank everyone for all of the kind messages they have received".
Keep scrolling to see the adorable new portrait, and to relive of some of Prince George's most adorable moments.
The photo, which was taken by royal photographer Chris Jackson, was posted on the Kensington Palace Instagram account.
The picture, taken at Kensington Palace ahead of his birthday on Saturday, captures a smiling future king.
The two-year-old toddler is already practicing her royal wave, she happily greeted the waiting cameras on the Cambridges' official visit to Poland and Germany.
Jackson has been snapping away this week on the Cambridge tour of Poland and Germany, which wraps up Friday.
In other photos, George and Charlotte were seen looking outside the plane's windows.
It might be hard to believe it, but July 22 this year marks four years since the birth of Prince George.
George is joining private day school Thomas's Battersea in September, where fees cost £17,604 a year.
The couple also released a new photograph of Prince George's little sister, Princess Charlotte, when she turned two on May 25.