Una, 35, shimmered in a sexy metallic jumpsuit as she joined husband Ben Foden at The Sparks Winter Ball on Tuesday night.
The celebrity couple are the current presidents of the Sparks charity, which aims to improve the lives of children affected by medical conditions.
Una also performed at the event, held at the Roundhouse in London, and hosted by sporting legend Sir Matthew Pinsent CBE and Sally Gunnell OBE.
Last year's ball raised over £285,000 for pioneering children's medical research.
Irish singer Una has reason to be smiling after announcing two very special live shows to coincide with the release of her debut solo album, The Waiting Game.
Una will play London's St Pancras Old Church on 15 February, followed by a gig at Dublin's The Sugar Club on 16 February.
Tickets are on sale from 10am today.
"I am so excited to take my brand new album The Waiting Game live to the stage for my very own headline shows in Dublin and London," said Una.
"I can't wait to hit the road with my live band and hope to see you there!"
Una's been working on her solo music while The Saturdays are on hiatus. The Waiting Game is described as a mix of "magnetic folk, pop and rock melodies" blended with the country music of Una's childhood.
Her debut solo single will be called 'Stay My Love' and is a collaboration with Nashville star Sam Palladio. It's due to premiere next year.
We can't wait!
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