The Duke of Sussex, 39, jetted to London to see his father on Tuesday following the King’s cancer diagnosis.
But he was pictured arriving at London Heathrow at 1.30pm on Wednesday – just 26 hours after landing.
Harry was seen wearing a suit jacket, T-shirt and jeans as he began his return journey to California.
And he arrived at Los Angeles International Airport around 2.20am to reunite with wife Meghan and kids Archie, four, and Lilibet, two.
It is believed he spent his single night in London at a hotel, rather than a royal residence.
It comes as:
Harry had a brief reunion with his father on Tuesday, with the King delaying a helicopter flight to Sandringham so they could hold their first meeting in 16 months.
Their meeting was thought to have lasted little more than half an hour, with Harry and his entourage leaving Clarence House around 45 minutes after arriving.
Charles looked happy with the reunion as he was pictured for the first time since the Palace announced his cancer diagnosis on Monday.
An insider said: “Charles always keeps a tight schedule and had a planned itinerary to leave London to rest and recuperate in Norfolk.
“He is very fastidious about time-keeping but it was significant that he delayed the flight to Sandringham when he knew Harry was visiting.”
There was no reunion with William, though.
Sources had earlier said the Prince of Wales had “no plans” to see his brother during his brief stint in the UK.
It comes as Wills made a return to public engagements on Wednesday.
The prince publicly acknowledged his father’s health shock at a fundraising gala in London.
Inside Charles’s 30-minute reunion with Harry after King delayed helicopter to Sandringham so he could welcome his son
KING Charles spent 30 minutes with estranged son Harry — their first meeting in 16 months.
The Duke flew 5,000 miles from the US to London after his dad’s cancer diagnosis.
The Duke of Sussex, 39, landed at Heathrow at lunchtime following a ten-and-a-half hour overnight flight.
He was whisked to London while Charles, 75, delayed a helicopter flight to Sandringham so they could hold their first meeting in 16 months.
The King was said to be “doing very well” and “entirely his normal self”.
A friend who saw His Majesty said: “If you didn’t know there was anything wrong with him you wouldn’t know.”
Another Palace source said the King was “on his usual good form”, and “just a little frustrated that his condition has affected not just his own plans but impacted on others”.
He cracked a joke about “getting away from it all” during a speech at a fundraiser for the London Air Ambulance Charity.
Wills was also heard thanking Brits for their well-wishes ahead of the event.
Wills told guests at London’s Raffles Hotel: “Thank you for being here. And thank you to all those whose hard work has made this evening possible.
“I’d like to take this opportunity to say thank you, also, for the kind messages of support for Catherine and for my father, especially in recent days. It means a great deal to us all.
Then in a light-hearted joke amid a stressful past three weeks, he added: “It’s fair to say the past few weeks have had a rather “medical” focus.
“So I thought I’d come to an air ambulance function to get away from it all.”
William also shook hands and posed for a photograph with Tom Cruise, before the pair chatted for several seconds and the Hollywood star gently patted the prince on his arm.
The prince also acknowledged the Hollywood actor in his speech.
He added: “I should also take this opportunity to give a mention to my – our – fellow pilot, Tom Cruise.
“Tom, huge thanks for supporting us tonight. And if you wouldn’t mind not borrowing either of the new helicopters for the next Mission Impossible, it would be appreciated.
“We have all seen on our screens that – how can I put it – you seem to have a different take on ‘normal wear and tear’ to the rest of us.
“It’s not the kind that buffs out, that’s for sure. Anyway, my thanks to everyone. You are all, each and everyone, lifesavers.”
Will did not mention Harry during the speech.
It came hours after he held an investiture at Windsor Castle.
The event was his first engagement after pausing his diary for three-and-a-half weeks to care for Kate and their three children following his wife’s abdominal surgery last month.
William was seen smiling and joking as he handed out gongs at the ceremony.
Working members of the Royal Family are said to be continuing with public engagements in the King’s absence.
Kate, though, is unlikely to be seen carrying out any frontline duties until after Easter, sources say, as she continues to recover.
William and Camilla are expected to share the weight of the King’s royal duties and engagements.
But the heir is understood to not be returning to full-time duties yet and instead “remains focused” on looking after his family.