The track will follow the likes of previous singles ‘Money On My Mind’ and ‘Restart’.
Royal Blood’s album debuts in first place, whilst Kate Bush sets a new Official Charts record.
This week’s round-up features Sam Smith, The Script, The Kooks and Maroon 5.
The accompanying video for ‘I’m Not The Only One’ features Glee star, Dianna Agron.
‘I’m Not The Only One’ will be the fourth single taken from Smith’s number one début album.