The 48-year-old, who is taking on Teen Angel in the iconic production, looked absolutely sensational in the fabulous, yet, unexpected get-up, consisting of a lilac satin blazer dress and sizzling thigh-high silver encrusted boots.
With her long mane tied up high and styled in a plait with pink and purple hair extensions, the mum-of-two - who will soon perform at her one-off special gig this summer - seriously served up some glamour.
"Meet… Teen Angel," she wrote in the caption. "I'm excited to be joining the West End cast of @greasewestend for a limited time at the Dominion Theatre from 2 June! Tickets available now xxx."
Upon seeing the post, Louise's followers went wild. "Oh. My. God. Wow Lou!" mentioned one, while another said: "Yessss Lou!!! You looked wicked! See you on the 2nd." A third post read: "As if you couldn't be any more stunningly beautiful & sexy, you go and don this striking outfit for a ravishing photoshoot!!!"
The pop sensation is set to perform in the West End from 2 June until 29 July. Speaking about her latest project, Louise previously gushed: "As the biggest fan of Grease growing up, I was thrilled to be asked to join the cast in the role of Teen Angel."
She continued: "Traditionally seen as a male role, I'm excited to be given the opportunity to shake it up and play it from a new perspective under the direction of Nikolai Foster."
This isn't the first time the Stay chart-topper has starred in a hit musical. Making her stage debut in 2017, Louise starred as Sally Bowles in the national tour of Cabaret. And in 2019, the songstress made her West End debut as Violet Newstead in Dolly Parton's hugely popular, 9 to 5 The Musical.
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