The 20-year-old star pleaded with fans outside his hotel in Bogota, Colombia, to "keep the noise down" in the early hours of Friday morning so he can get enough rest before the 'You and I' heartthrobs perform the first show on their 69-date tour.
He wrote on Twitter: "Big day tomorrow! Gona try and get some sleep! Gona be hard!
"I honestly think this hotel is made of paper! Haha! It feels like the people outside are in my room haha! Not a chance of sleep tonight
"Guys! May I ask you to keep the noise down please ! All of our crew are tired! and we have a big day tomorrow! Don't want to sound angry !
"Thank you ! Much appreciated ! Big day for all tomorrow! Love you lots! Goodnight! Xxx (sic)"
Niall's desperate bid for sleep came after he and his bandmates - Harry Styles, Zayn Malik, Liam Payne and Louis Tomlinson - had a "long day" of rehearsals putting the final touches on their stadium show.
He wrote: "Just done a couple of final run throughs of the show! Can't wait now! Been a long day and the fans have been incredible in bogota! Much love (sic)"