Band Aid 20 was the 2004 incarnation of the charity supergroup Band Aid. The group, which included Daniel Bedingfield, Dido, Justin Hawkins of The Darkness, Thom Yorke and Jonny Greenwood of Radiohead, Chris Martin of Coldplay, Bono of U2, and Paul McCartney, re-recorded the 1984 song "Do They Know It's Christmas?", written by Band Aid organisers Bob Geldof and Midge Ure.

The song was recorded on 14 November 2004, to benefit Sudan's troubled Darfur region, and was released that same month. The single became the UK's biggest seller of 2004 as well as the Christmas number one.

Bono and Paul McCartney were the only artists from the original Band Aid to lend their voices to Band Aid 20. There was a reported dispute over the line 'Well tonight thank God it's them, instead of you', which Bono sang on the original version. Justin Hawkins, of The Darkness, laid down a version of the line, as did Robbie Williams, but Bono insisted on re-recording his version, which was eventually used on the record.

Travis lead singer Fran Healy, who played guitar on the recording, said, "It's dead exciting. When [the 1984 version] was first recorded, I was 11 and I went everywhere looking for it and I couldn't find it, and now we're going to do the follow-up to it. It's going to be great, McCartney's doing it, Bono's going to sing his own line, [and] we're going to help out with some music, with Nigel Godrich, who produced the single. I really wanted to get Franz Ferdinand involved in it -- I think they're going to do it, although I haven't spoken to Midge Ure for about a week now."

"Midge did a thumbnail sketch of the original with new music on it," Healy continued. "He's got the Darkness doing the guitars at the end, and he's changed the arrangement of it. He shipped that over to L.A. where Nigel was working with McCartney. If it turns out absolutely shit, it does not matter. What I will say is you've got to buy the record because it's the only record that's going to save lives this side of Christmas, and you can't ask for more than that."

A special documentary titled Band Aid 20: Justice, Not Charity, which went behind-the-scenes of the new recording, was broadcast by BBC One on 6 December 2004.

The Band Aid 20 single was first played simultaneously on The Chris Moyles Show (on BBC Radio 1) and the breakfast shows on Virgin Radio and Capital Radio, at 8 am on 16 November 2004. The music video was first broadcast in the UK simultaneously over multiple channels, including the five UK analogue terrestrial channels, at 5:55 pm on 18 November 2004, with an introduction by Madonna.

One of the new ways to buy the song, by downloading it from the internet, hit a problem when Apple Computer's iTunes Music Store initially refused to supply it, due to their fixed-pricing policy. A partial solution was reached after a few days, enabling UK users to download the song at the standard iTunes price, with Apple donating an extra amount (equivalent to the price difference) to the Band Aid Trust.