In a message posted to Twitter, the Royal Family said: “Wishing The Duke of Sussex a happy birthday today!”
The post was accompanied by a series of images of Harry on various projects taken while he was a working member of the Royal Family.
The Duke and Duchess of Cambridge posted a separate message, alongside a picture of Harry smiling. “Happy birthday Prince Harry!” they wrote
Wishing The Duke of Sussex a happy birthday today! 🎈 pic.twitter.com/W1MJC9cGBn
— The Royal Family (@RoyalFamily) September 15, 2021
Prince Charles and his wife, the Duchess of Cornwall, also sent well wishes to his youngest son on Twitter.
“Wishing The Duke of Sussex a very Happy Birthday today!” they wrote.
The Duke of Sussex now lives in California with his wife Meghan Markle and their two children, Archie and Lilibet.
He and Meghan stepped down as senior royals in early 2020.
Harry has yet to announce how he will celebrate his milestone – though it is tradition for royals to celebrate their birthdays with a charitable donation.
Last year, he chose to support CAMFED, a charity that promotes girls’ education in Africa.
Meghan turned 40 in August – and launched a new initiative to help women who lost their jobs due to the pandemic return to work.
Happy Birthday Prince Harry! 🎈 pic.twitter.com/Lw1nR9wNDl
— The Duke and Duchess of Cambridge (@KensingtonRoyal) September 15, 2021
The project, named 40×40, suggested people around the world donate 40 minutes of their time to help unemployed women. It was backed by British Vogue editor Edward Enninful and actress Melissa McCarthy.
“Because I’m turning 40 I’m asking 40 friends to donate 40 minutes of their time to help mentor a woman who is mobilising back into the workforce,” the Duchess said as she launched the project.
“Over 2 million in the US alone and tens of millions around the world have lost their jobs due to Covid, and I think if we all do it and all commit 40 minutes to some sort of act of service we can create a ripple effect,” she said.
It comes after it was confirmed the Duke of Sussex is taking part in a military event alongside US First Lady Jill Biden.
Wishing The Duke of Sussex a very Happy Birthday today! 🎂 pic.twitter.com/rGhu2BtsX3
— The Prince of Wales and The Duchess of Cornwall (@ClarenceHouse) September 15, 2021
Harry, who spent 10 years in the Army, is co-hosting the virtual event honouring those taking part in the Warrior Games which celebrates injured active duty and veteran US military service members.
He is appearing alongside Dr Biden, Secretary of Defence Lloyd Austin and Ken Fisher, CEO of Fisher House Foundation.
Harry is attending “in support of these athletes and their families”.
The duke was expected to attend in person as the 2021 Warrior Games was slated to take this week in Orlando, Florida, but it was cancelled due to coronavirus-related concerns.
The duke, who founded the Invictus Games Foundation which helps soldiers through their recovery via international sports competitions, also served two frontline tours to Afghanistan.
A White House statement said the Warrior Games shares a “deep bond” with the Invictus Games.