Buenos Aires police said in a statement that Payne, 31, fell from the third floor of the Casa Sur Hotel in the trendy Palermo neighbourhood of Argentina's capital, resulting in "extremely serious injuries."
Medics confirmed his death on the spot, the statement said.
Alberto Crescenti, head of the state emergency medical system, said on Argentina's Todo Noticias TV channel that Payne fell into a courtyard but declined to answer further questions about the incident, including whether he jumped from the balcony or fell by accident.
Crescenti told Todo Noticias that authorities were investigating the circumstances of his death and conducting an autopsy.
Fans took to Payne's most recent Instagram post, where the late singer shared a tribute to American documentary filmmaker Morgan Spurlock, who died in May.
View this post on Instagram
"Rest in peace, Liam, you were my childhood," one person wrote, while another commented, "This can't be real."
"Heartbroken right now," another wrote.
"RIP Liam … I can't believe this is real … absolutely heartbreaking …," German DJ Anton Zaslavski, also known as Zedd, wrote on X.
Irish singing duo Jedward took to X to write, "Sending strength to Cheryl and his son Bear and all the One Direction Family."
Paris Hilton paid tribute to Payne on social media.
So upsetting to hear the news of @LiamPayne passing😢 Sending love and condolences to his family & loved ones. 🙏 RIP my friend🥺
— Paris Hilton (@ParisHilton) October 16, 2024
The socialite called the news "upsetting" in a post on X and sent her "love and condolences" to his friends and family.
MTV's Latin American branch posted X: "Our hearts are absolutely broken, and we wish much light and strength for his family and loved ones."
Earlier on Wednesday, Payne appeared to post on Snapchat about his trip to Argentina, talking about riding horses, playing polo, and looking forward to returning home to see his dog.
"It's a lovely day here in Argentina," he said in the video.
Argentine media reported that Payne was in Buenos Aires to attend the concert of his former One Direction bandmate Niall Horan.
Payne was one of the founding members of One Direction, one of the most successful boy bands of the past decade.
One Direction formed in 2010 when they auditioned for the British singing competition series The X Factor.
After each singer failed to make it through the competition as a solo act, Simon Cowell and his fellow judges combined them into what would become a successful pop group.
The band became known for their pop sound and romantic hits like What Makes You Beautiful. They had six Top 10 hits on the Billboard charts by the time they disbanded in 2016. They had a loyal fan base, many of whom were teen girls who became known as Directioners.
Payne released his debut solo album LP1 in December 2019, which included the singles Polaroid and Familiar.
Payne had a seven-year-old son, Bear Grey Payne, with his former girlfriend, the musician Cheryl, who was known as Cheryl Cole when she performed with Girls Aloud.
He is also survived by his parents, Geoff and Karen Payne, and his two older sisters, Ruth and Nicola.
Representatives for Payne did not immediately return emails and calls.
With AP and PA.
