The 41-year-old's wife Meghan posted the photo in Instagram to mark Father's Day.
It comes as Harry and Meghan are expected to travel to Britain in July with Archie, seven, and Lilibet, five, marking the children's first visit to the UK in four years.
The trip is expected to include events linked to Harry's Invictus Games and could see the family stay in a royal residence, with reports suggesting Buckingham Palace is among the options under consideration.
The visit comes as efforts towards a reconciliation between Harry and King Charles continue following years of family tensions after the Sussexes stepped back from royal duties in 2020.
Sharing a video montage on Instagram for Father's Day, Meghan told Harry: "They're so lucky to have you.
"We all are.
"Happy Father's Day to our one and only."
The footage included images of Harry embracing Archie and Lilibet, with Archie wearing an England football shirt while hugging his father in support of the team's World Cup efforts.
The post comes amid renewed attention on Harry's relationship with the Royal family.
In May 2025, Harry told the BBC he hoped for a reconciliation with relatives following years of public disagreements and legal disputes surrounding his security arrangements in Britain.
Harry has remained a prominent public figure through his charitable work and his role as founder of the Invictus Games, the international sporting event for wounded, injured and sick servicemen and women.
The next edition of the competition is due to take place in Birmingham in 2027, with Harry expected to attend a series of promotional engagements in London and Birmingham between July 6 and 10.
According to reports, an arrangement has been reached that would allow Charles to spend time with Archie and Lilibet during the visit.
The King has not seen his grandchildren in person since celebrations for Queen Elizabeth II's Platinum Jubilee in June 2022.
The Sussexes have rarely travelled to Britain as a family since relocating to California after their departure from royal duties, a period widely referred to as "Megxit".
Harry has repeatedly cited concerns over security after the removal of automatic state-funded police protection following the move.