is the irresistible face of Charlotte Tilbury Beauty's new Pillow Talk campaign, the Daily Mail can reveal.
The Hollywood actress, 44, who is currently expecting her second child with boyfriend Oli Green, 29, smoulders in pink lingerie for the brand-new advertisement, pouting with the blush lip tint gracing her lips.
Lying atop a bed, Sienna conceals her bump beneath delicate lace, just four months after revealing she is pregnant with her third child at the .
With her freckled face resting on her hand and her blonde hair cascading in loose waves, Sienna radiates effortless glamour in the latest chapter of the global luxury beauty brand's iconic Pillow Talk collection.
Charlotte Tilbury MBE, chairwoman and makeup artist to the stars, has a longstanding friendship with Sienna and chose her as the muse for the Pillow Talk in Bloom campaign as she awaits the arrival of her third child.
Sienna, who returned to Instagram on Friday after an eight-year hiatus with a picture of her baby bump, is already a mother to 13-year-old daughter Marlowe, whom she shares with ex-fiancé, actor , and a two-year-old daughter with Oli, with the couple now expecting their second child together.
Sienna Miller is the irresistible face of Charlotte Tilbury Beauty's new Pillow Talk campaign, the Daily Mail can reveal
Sienna was joined in the glossy campaign by Charlotte's niece Bella Tilbury, as the pair lay side by side while modelling the new Pillow Talk Blush Balm Lip Tint.
The model, who has worked with fashion houses including Burberry and Gucci, before becoming an ambassador for Marks & Spencer, flashed a hint of skin beneath pink lace lingerie.
Ahead of the beauty reveal, Sienna returned to Instagram for the first time since 2017.
Her celebrity friends were quick to comment on the post, which showed off her growing baby bump, including actor Justin Theroux, who joked: 'Oh my God, the non-stop posting with you. It's relentless.'
Lindsay Lohan and Poppy Delevingne were among those who celebrated Sienna's return to social media, sharing emojis and welcome-back messages.
Presenter Laura Whitmore, 40, who is also currently pregnant, replied: 'Relatable.'
It comes as Sienna's sister, Savannah Miller, revealed she is also expecting a baby at the age of 47 with her husband, James Whewell - 21 years after the birth of her eldest daughter.
She announced the news on Instagram, writing: 'Our longed-for miracle baby is joining the gang in August.'
The actress, who is currently expecting her second child with boyfriend Oli Green, smoulders in pink lingerie for the brand-new advertisement, pouting with the blush lip tint gracing her lips
Sienna, who has worked with fashion houses including Burberry and Gucci, before becoming an ambassador for Marks & Spencer, flashed a hint of skin beneath pink lace lingerie
Ahead of the beauty reveal, Sienna returned to Instagram for the first time since 2017 to showcase her growing baby bump
Speaking about the signing, Charlotte Tilbury said: 'Darling, I am so excited to reveal my wonderful friend Sienna Miller as the star of my Pillow Talk in Bloom campaign.
'Sienna is the ultimate beauty muse to bring this campaign to life. She has always had this effortless, magnetic allure – she's a true style icon with an enduring screen presence and a natural radiance that makes her so captivating.
Pillow Talk in Bloom is the next chapter of my globally adored Pillow Talk phenomenon – a reimagined world of fresh, romantic, natural beauty – and Sienna embodies that spirit perfectly.
'Seeing her on set in the English countryside, surrounded by wildflowers and soft autumn sunlight, she looked irresistible in her pretty Pillow Talk look with just-kissed lips, love-blushed cheeks and a dreamy, radiant glow.
'Sienna and I have known each other for years, so welcoming her into her very first Charlotte Tilbury campaign felt like a perfect full-circle moment.
'And I know how much she loves Pillow Talk, darling it has been in her makeup bag for years, so bringing her into this new era was like making a Pillow Talk dream come true.'
