According to the Official Charts Company (OCC), more than 132,000 copies of Ghost were purchased in the UK over the seven days since its release.
It means the young artist from Tetney, Lincolnshire now has the fourth fastest selling single of 2014 so far.
Ghost was co-written with OneRepublic frontman Ryan Tedder. His CV also includes writing work on tracks for the likes of Leona Lewis, Ellie Goulding and Adele.
Ella said: ‘It feels incredible. I just can’t believe it! I’ve taken my time away, writing, and coming back into it with all this support is amazing.
‘When you think about the people Ryan works with, it was definitely overwhelming being in the same room as him. He gets to pick and choose who he works with, and to say I got to write my first single with him is insane!’
Ella first came to fame two years ago after appearing in the 2012 series of X-Factor alongside eventual winner James Arthur. She was knocked out in the seventh week of the live rounds of the competition.
Elsewhere, Rik Mayall’s Noble England reached number seven in the charts after a fan-led social media campaign to get the late comedy star to number one following his recent death.
In the album charts, Kasabian’s latest album 48:13 has reached the top spot giving the band their fourth number one.
Their chart success pre-empts a 50,000 capacity homecoming gig in Leicester and a headline slot at this year’s Glastonbury.