We're used to seeing the 2006 X Factor winner belt out her hits, but the 28-year-old is now swapping the stage for the big screen in her first film role.
It's not yet known what character Leona will play, but the 'Collide' singer began rehearsals at the beginning of this month, with filming only starting in Italy last week.
Leona will join comedienne Katy Brand and Sense & Sensibility actor Greg Wise, as well as Being Human actress Annabel Scholey (Taylor) and rising stars Hannah Arterton (Maddie) and Giulio Berruti (Raf).
After filming some scenes last week, she tweeted: "Just wrapped for the day! So excited for you guys to see this, such great moments being captured. Lucky to work with amazingly talented ppl."
The plot of the film is as follows: "After a whirlwind romance in Italy, Maddie is preparing to marry gorgeous Raf and has invited her sister Taylor to the wedding. Unbeknownst to Maddie, however, Raf is Taylor's ex-holiday flame, and the love of her life."
Holiday!, dubbed as a "rollercoaster ride of a musical" will feature a soundtrack of 80s hits including Madonna's 'Holiday', Cyndi Lauper's 'Girls Just Wanna Have Fun', and Wham's 'Wake Me Up Before You Go Go'.
Producer James Richardson said: "Holiday! promises to be a classic feel good love story, with spectacular choreography and the greatest hits of the 80s."
Holiday! will be released by Vertigo Films in summer 2014.
Watch Leona's video for 'Trouble' below: