The charity single shifted more than 312,000 copies last week, making it 2014’s fastest-selling single so far.
Organiser Bob Geldof thanked the nation on BBC Radio 1 and said he was “so proud”.
It is the fourth version of the track to be released, and featured artists include Bastille and Rita Ora. Each version has made it to number one.
Geldof said the UK version of the song is also number one in France and other versions are number one in 61 countries.
He added: “I expected it, but did I expect it in such vast and willing numbers? No.”
All proceeds from the song go towards the fight against Ebola in West Africa.
Bono, Ed Sheeran, One Direction, Emile Sande and Ellie Goulding are also among those who perform on the single.
Sales of Band Aid 30 are expected to rise once a physical CD version is released on 8 December.