This article is part of Yahoo's 'On This Day' series.
One of the guarantees of Christmas, along with festive food, drink and presents, is the traditional onslaught of seasonal music.
Whether it's your classic Christmas tunes from the likes of Mariah Carey, Michael Buble, Slade or Wizard, it isn't the festive season without those novelty pop hits we've all heard dozens of times (at least) before.
Given plenty of Christmas hits get rolled out every single year, it's fair to say the stars behind them have benefitted nicely from those festive royalties.
But which chart-topper is the best-selling Christmas song of all time, worldwide? We looked at the stats to find out.
5. Mistletoe - Justin Bieber
The Canadian superstar's festive effort, released in 2011, sold 164,000 copies in its first week of release. By January 2012, estimated digital sales of the song had reached 722,000, the most a Christmas song has ever sold in a calendar year.
One of only two songs to have hit multi-platinum status, Bieber's seasonal hit has now sold at least two million copies, as of 2015.
4. Do They Know It's Christmas? - Band Aid
The 1984 charity single, featuring a supergroup including the likes of Boy George, Bono, George Michael, Sting and many more, shifted more than 2.5 million copies in the U.S. alone, according to the New York Times, and 3.8 million in the UK.
Written by Bob Geldof and Midge Ure in response to a series of distressing BBC News reports by Michael Buerk on the Ethiopian famine, it entered the UK charts at No.1 and stayed there for five weeks, topping the charts at Christmas.
It's since been re-recorded with different artists three times, in 1989, 2004 and 2014 - all of which were also charity records.
3. All I Want For Christmas Is You - Mariah Carey
As Christmassy as pigs in blankets and mulled wine, Mariah's iconic festive hit, released in 1994, is a six-time multi-platinum award winner, and has surpassed 16 million total worldwide sales.
Described by The New Yorker as 'one of the few worth modern additions to the holiday cannon', in 2016 it was credited as the Christmas song with the most digital downloads ever. Mariah's Christmas number also reportedly sold over 3.2 million copies in 2016 alone.
Not only is it in the top three best selling Christmas songs ever, it's even the 12th-best selling single of all time.
2. Silent Night - Bing Crosby
Bing Crosby's instantly recognisable Christmas classic, first released in 1935, is now thought to have shifted more than 30 million copies.
Originally a Christmas carol composed in 1818 by Franz Gruber in Austria, it has become one of the most popular festive songs in the world and been translated into more than 40 different languages.
It's also been recorded by, among others, Elvis Presley, Simon & Garfunkel, Stevie Nicks, Tori Amos and Andrea Bocelli.
Crosby's interpretation remains the most popular version of all time, however - but it's not even his most successful Christmas song....
1. White Christmas - Bing Crosby
Not only is White Christmas the best-selling festive tune ever, it's the biggest-selling single of all time with an estimated 50 million sales.
Originally written by composer and lyricist Irving Berlin for the film of the same name, it was released in 1942 and won an Oscar for Best Original Song.
After being covered by Crosby, it spent 11 weeks on top of the Billboard chart, and it's since become the most recorded-Christmas song, with over 500 different versions.
Despite its recurring global success, however, White Christmas has never actually been a No.1 in the UK - peaking at No.5 in 1977.