The Duke of Sussex was filmed screaming as he ventured through a haunted maze with Jimmy Fallon on his late-night talk show, following a week of high-profile appearances in New York.
Harry did not take part in a typical interview with host Fallon, instead opting to become the first surprise guest to test a Halloween experience called Jimmy Fallon's Tonightmares at the Rockefeller Centre in the Big Apple.
His appearance on the TV show comes after he carried out days of engagements in an east coast trip without the Duchess of Sussex during UN General Assembly High-Level Week and Climate Week.
The segment broadcast on US network NBC saw swear words bleeped out as Harry, who had a camera strapped to his chest, appeared jumpy while wandering through the maze.
Prince Harry and Jimmy Fallon took part in an unusual horror maze segment on US TV
The Duke's participation on the programme was a far cry from other events he went to this week
In a comical moment, the duke compared a haunted figure to a famous Canadian singer.
'Is that Michael Bublé? Good job buddy,' Harry said.
At the end of the experience, Harry pretended to throw a punch after being frightened by an actor while posing for a picture with Fallon.
'Brace yourself for 10 spine-chilling rooms that bring Jimmy's worst nightmares to life with sinister characters and scares around every corner,' The Tonight Show's YouTube page said.
It comes after Harry appeared as a star guest in the Clinton Global Initiative in New York on Tuesday, where he delivered a passionate speech calling for action to tackle the 'pervasive threat' the online world poses for children.
Speaking alongside members of Lesotho's royal family at the United Nations HQ, Harry told how his charity Sentebale's name came from the country's Sesotho language - meaning 'Forget me not'.
He had begun by saying in English, 'Your Majesty, ladies and gentlemen, distinguished guests and friends' - and then repeating the greeting in Sesotho: 'Morena, basali le bahlomphehi, baeti ba hlomphehang le metsoalle.'
He also on Tuesday addressed an audience about the 'terrifying' impact of climate change as he marked the fifth anniversary of his sustainable tourism organisation Travalyst
Harry is pictured during his first visit to Lesotho as a 19-year-old, in March 2004
Prince Harry has been speaking of his love for Lesotho - and addressing guests in both English and Sesotho - at an event held at the United Nations HQ in New York on September 24
He recalled first visiting Lesotho during a gap year in 2024 between leaving Eton and starting at Sandhurst military academy, as he spoke alongside fellow delegates including the country's King Letsie III and Queen Masenate Mohato Seeiso.
Harry, 40, said: 'The Lesotho royal family, as well as Lesotho itself, has been a pillar of strength for me over the last 20 years, welcoming me with open arms and such kindness.
'The beautiful mountain kingdom feels like a home away from home.
'That friendship has only grown stronger as we've worked together to tackle some of the most pressing challenges facing the Lesotho people and the wider world.'
Harry told of helping to set up Sentebale two years after his first visit , adding: 'The charity was founded in honour of our mothers and symbolises our pledge to always remember and advocate for the most vulnerable among us.
'Our mission at Sentebale is simple yet incredibly important - to help vulnerable children and young people across Lesotho and Botswana to access vital health services, receive care and support, and develop the life skills necessary to thrive.
'By focusing on the youth we're breaking generational cycles of trauma and outdated beliefs.'
The duke's Archewell Foundation launched the Parents Network last month as a support network for parents of children affected by online harm.
His appearance on the TV show also comes in the week a US judge ruled his US visa application should remain private despite him admitting taking drugs in his memoir.
Harry is set to briefly return to the UK to attend the WellChild annual awards next Monday.