It's been announced today that the pair will take up roles in the new production of Waitress The Musical.
Lucie rose to fame on The X Factor and in 2017 represented the UK at Eurovision. She's since gone on to make her name in musical theatre with roles in Rent and Legally Blonde.
She will play Jenna, taking over from American performer Katharine McPhee from June 17.
Joining her will be former Pussycat Doll singer Ashley who last year made the final of Strictly Come Dancing.
Ashley tweeted: "Got some sweet news! I'm going to be playing Dawn in @WaitressLondon from 17th June. Yasss to some comedy singing and dancing fun!! Can’t wait! Hope to see you there 🥧"
Lucie posted to her Instagram: "I will never stop crying 😭 From June 17th I will be playing the role of Jenna in @waitresslondon 🥧 This show is absolutely stunning and I cannot believe my luck... I get to tell Jenna’s story every day and sing the gorgeous @sarabareilles tunes nightly. Genuinely, my dreams are coming true"
Based on the movie of the same name, Waitress The Musical features songs by Sara Bareilles and tells the story of Jenna a waitress and expert pie-maker who dreams of a way out of her small town and rocky marriage.
Meanwhile, Ashley is far from the only star of last year's Strictly making her debut in the West End.
You can currently catch her fellow finalist Faye Tozer in the run of Everybody's Talking About Jamie, while Love Island's Amber Davies is currently starring in 9 to 5 The Musical.
Strictly Come Dancing will return for a brand new series in the summer.
PIC Credit: Twitter/@WaitressLondon