The stunning reality star flaunted her mega-toned tum in RiRi's lace-up bralet, £25.
The monochrome floral print must be the star of the collection, with Lydia Bright rocking the matching maxi dress and Perrie Edwards sporting the co-ordinating shirt.
Millie completed her look with another Tinseltown favourite - a white skort, £25.99 from Zara, as worn by The Saturdays' Una Healy.
But despite Millie's chic outfit, her cute pup Herby totally stole the limelight.
He's a natural born poser!
What do you think of Millie's outfit? Let us know by commenting below as the best comment across the site each week wins £50!
Bikinis, babies and new mum style: top showbiz stories for Monday in pictures
Copyright: ITV Screengrab