Leigh-Anne originally auditioned for The X Factor as a soloist - as did her bandmates Perrie Edwards, Jade Thirlwall and Jesy Nelson.
The girls all failed to progress as individuals, and the judges put them into two different bands.
And their relationship appears to be going from strength to strength, as the smitten pair have also moved in together.
Fans have predicted that an engagement could be on the cards in the coming months.
Here are eight reasons we'd love to be Leigh-Anne's best friend...
She's part of one of the biggest pop bands in the world, so it's no surprise that Leigh-Anne gets invited to some very glamorous and prestigious events such as The BRIT Awards, The GRAMMY Awards and various MTV music awards.
And now, she's part of one of the world's most successful girlbands, adored by Mixers across the globe and in a happy relationship with footballer Andre Gray.
Here is everything we know about the brunette beauty...
As the band prepare to go on tour in 2019, Leigh-Anne's relationship with footballer Andre Gray is going very well, with fans thinking an engagement could be on the cards!No, she doesn't have a biological twin but she does have an older sister!Big sis Sairah reportedly signed up to be one of Love Island's reserves on the 2018 show but she's now loved up with her boyfriend Jigz.Before joining Little Mix and going on to achieve global domination after winning The X Factor in 2011, Leigh-Anne had just finished her A-Levels and was working as a waitress in Pizza Hut.She has her own fashion blog, called Leigh Loves, on Tumblr, where she treats fans with pictures of the clothes she loves.
" In November 2016 Leigh-Anne was shockingly attacked while eating at a 24-hour London restaurant.