The 41-year-old will now join the likes of Jennifer Lopez and Beyoncé in becoming the latest celebrity ambassador to front the company’s global advertising campaign.
She told People: 'I can't believe I get to be one of the L'Oréal Paris girls.
'I love playing dress-up, on stage or shooting videos, it's always been one of my favourite parts of being in a band.
'To get to work with such a modern, talented group of people is really exciting. I'm a lucky, lucky girl.'
She has been chosen to promote the brand’s Infallible Le Rouge lip colour and the commercial will air during this Sunday's Golden Globes.