The starlet joined her fellow Little Mix-ers as they hit the red carpet for the first showing of One Direction: This Is Us in Leicester Square, London.
Leigh-Anne totally hit the style mark in a black strapless jumpsuit, similar to a look worn by Victoria Beckham earlier this year.
And we reckon she got things spot on by pairing her sultry get-up with sleek, swept back tresses.
Michael Douglas, celebrity hairdresser and Silvikrin Style Director, gave us his top tips to recreate her look at home:
1. First of all, apply a volumising mousse (try Silvikrin Dual-Benefit 2 Day Volume & Hold Mousse, £2.99) through the lengths of your hair, then blow-dry upside down to get as much body as possible. This will ensure your hair doesn't fall flat or limp when slicked back.
2. Once completely dry, use straightening irons to straighten your hair in sections, going away from your face.
3. Using a large round bristle brush, brush all your hair on the top of your head backwards and behind your ears, fixing with short bursts of hairspray (try Silvikrin Maximum Hairspray, £2.19).
4. To achieve Leigh-Anne's wet-look effect, finish with a small 50p-sized amount of gel. Apply to the palm of your hand first before working from the roots to the mid-lengths of your hair, leaving the ends free to fall naturally down your back.
Try not to use too much gel - we're going for sleek, not greasy!
Will you be trying out Leigh-Anne's hairstyle? Let us know by commenting below as the best comment across the site each week wins £50!