In a move that will definitely please Directioners, Niall decided to take on the challenge in a white t-shirt, which promptly went see-through after he chucked the freezing cold water over himself.
Will Louis accept Niall's challenge?
Niall also nominated three celeb pals to take part in the charity challenge, picking footballer John Terry, his 1D bandmate Louis Tomlinson and Wimbledon champion Novak Djokovic.
As someone who’s completed the challenge, Niall’s in good company. So far, everyone from Justin Bieber and J-Lo to Taylor Swift and even Oprah Winfrey have also taken part.
The #icebucketchallenge social media craze started in the US and many participants are raising cash for charity, donating to the ALS Association in the US and Macmillan Cancer Support in the UK.