The former prison officer sold 149,000 copies of her first single to take the top spot.
According to the Official Charts Company (OCC), Sam’s release outsold Pharrell Williams’ Happy (number two) by more than two copies to one, making it one of the fastest sellers of the year.
All proceeds from the record single will be split between Great Ormond Street Hospital Children’s Charity and Together For Short Lives.
Sam said: ‘Being number one is absolutely amazing! It really is the icing on the cake and it means Great Ormond Street Children’s Charity and Together For Short Lives will benefit from the single which makes it extra special.’
Martin Talbot, chief executive of the OCC, said: ‘Congratulations to Sam Bailey, the UK’s official 2013 Christmas number one! X Factor winner one weekend, Christmas number one the next. Life can’t get much better than that, especially when you have taken the crown with one of the biggest weekly sales totals of the year.’
Meanwhile, AC/DC have scored their first ever UK Top 10 single today with Highway To Hell taking the fourth position.
Originally released in 1979, Highway To Hell returned to the chart following a fan-led social media campaign to stop the X Factor winner taking number one.
Nineties rave duo Altern 8 also returned to the Top 40 today for the first time in over 22 years with Activ 8 (Come With Me).