The sweet snapshot, captured by Chris Allerton and shared to the Sussex Royal Instagram page, features Prince Harry holding baby Archie with Prince Charles looking on, and was appears to have been taken at Archie’s christening earlier this year.
“Happy birthday to His Royal Highness The Prince of Wales - Sir, Pa, Grandpa!” the accompanying caption reads.
The image, of Archie in his Baptism robes, will no doubt delight royal fans as previously the Duke and Duchess of Sussex have only released a few family photos from their son’s special day.
The occasion took place in a private chapel at Windsor Castle in July this year.
The picture share comes as it has been revealed the Duke and Duchess of Sussex are not expected to join the Queen for Christmas this year.
Every year, the royal family gathers at Sandringham, the Queen’s Norfolk estate, for the festive period.
But several reports have claimed that Harry and Meghan are considering joining her mother Doria Ragland in the US to celebrate Archie's first Christmas there.
The couple, who are set to begin a six-week break from royal duties next week, have plans to travel to the US for Thanksgiving, and there is a chance the trip could be extended to include the festive period.
The picture has been released in celebration of Prince Charles, who is celebrating his 71st Birthday today.
It was revealed yesterday that the Prince of Wales is set to launch his own clothing line.
The royal's charity, The Prince's Foundation, has teamed up with Yoox Net-a-Porter to produce a capsule collection for both men and women.
The Modern Artisan, will launch with an autumn/winter collection next summer.