The former Made In Chelsea star proved there's nothing better than a little black dress while attending the launch of celeb make-up artist Charlotte Tilbury's Backstage Beauty Booth at Fenwick on Bond Street.
Millie launched her own clothing range, the Millie Mackintosh Collection, in September, and she's taken every opportunity to show it off!
For this occasion, the fashionista rocked a figure-hugging black frock with three-quarter length sleeves and a ruched, asymmetric skirt, which is available to buy for £70.
Showcasing even more of her enviable wardrobe, Mills added heaps of va-va-voom with a pair of sultry over-the-knee boots, giving her ensemble a slight hint of colour with an autumnal berry red manicure.
She wore her dazzling engagement and wedding rings (courtesy of hubby Professor Green), while styling her caramel brown tresses in perfect bouncy curls which effortlessly draped past her shoulders.
Being a make-up artist herself Millie always nails things on the beauty front, and this time was no different with the starlet adding smokiness to her peepers with grey and black eyeshadow, teamed with a sweep of warm bronzer on her cheeks and a dab of peachy nude lipstick.
And it's hardly surprising the starlet showed up to show her support for Charlotte - the pair have been pals ever since Millie appeared in a couple of Charlotte's YouTube make-up tutorials.
Chatting to Reveal about their friendship, Millie said: "She's amazing, I've loved her since I was like 10!
"She loves my fake lash collection, and she's really keen on my fashion line too. You know the skirt I wore on the night [of my clothing launch party], the blue one, she's already ordered it. I like her make-up and she likes my clothes!"
What do you think of Millie's LBD? Let us know by commenting below as the best comment across the site each week wins £50!
Reveal is now on Google Plus! Join us here for the latest pictures, fashion and celebrity news!
Got an iPad or iPhone? Reveal Mag is specially designed to fit!