Sienna Miller, 42, looks every inch the glamorous film star in a sexy black dress as she holds hands with boyfriend Oli Green, 27, on date night in Cannes

Sienna Miller looked every inch the glamorous film star in a sexy black dress as she stepped out in Cannes amid the annual film festival on Saturday night.

The actress, 42, was joined by her boyfriend Oli Green, 27, as they enjoyed a date night and looked as loved-up as ever as they held hands.

She showed off her incredible figure in the slinky, figure-hugging black dress as she stepped out – just four months after welcoming her second child. 

The stunning off-the-shoulder number flaunted her assets and was teamed with strappy black heels and a matching bag.

She is in Cannes to promote her new film Horizon: An American Saga where she stars opposite Kevin Costner.

The actress, 42, was joined by her boyfriend Oli Green, 27, as they enjoyed a date night and looked as loved-up as ever as they held hands

She wore her blonde tresses in a perfect bouncy blow dry and opted for a natural makeup look.

Beside her Oli looked smart in a brown suit, white shirt and black shoes as he held hands with his beautiful partner. 

Horizon: An American Saga chronicles a multi-faceted, 15-year span of pre-and post-Civil War expansion and settlement of the American west.

Sienna and her boyfriend Oli welcomed their first child together, a baby girl, in January. Sienna also has a daughter Marlowe, 10. 

The actress barely aged a day since starring in Layer Cake and Alfie more than twenty years ago – and previously credited yoga and her love of Marmite as the secret to her age-defying looks. 

Last month Sienna joined the likes of make-up artist Charlotte Tilbury and models Poppy Delevingne and Cora Corre at Lady Lola Bute’s 25th birthday party, held at the family’s Mount Stuart House on the Isle of Bute. 

Sienna stood out from the crowd in a £3,900 floor length silk mesh dress created by Annie Doble of Annie’s Ibiza.

It featured hand-beaded crystals in the shape of a cobweb and a backless design, while the sheer nature of the dress highlighted her lithe figure. 

She showed off her incredible figure in the slinky, figure-hugging black dress as she stepped out – just four months after welcoming her second child

The next morning Oli was seen sunbathing while Sienna attended a photocall

He relaxed at the Eden Roc Cap Antibes Hotel in the sun

He wore stylish green swimming shorts

He didn’t have a care in the world as he sunbathed

He relaxed solo on the pontoon

She teamed the look with a nude bodysuit and a bronzed tan, having just got back from a family holiday in Croatia. 

The designer also produced a custom-made outfit in a 1920s Egyptian fabric for Lady Lola. 

As Lola and Annie shared photos of the bash on Instagram, Sienna firmly cemented her status as a fashion icon as she posed for a photo with Annie and Camille Charriere.

Sienna previously gave an insight into her health and fitness regime and told Vogue: ‘I do yoga three times a week…more because I’m just searching for some equanimity.

‘It’s very easy to feel exhausted by these schedules and time zones.’

He was topping up his tan on the day out

Her outing comes after she showcased her incredible figure in a £3,900 gown at a star-studded birthday party, just four months after giving birth to her second child 

Sienna and her boyfriend Oli welcomed their first child together, a baby girl, in January. Sienna also has a daughter Marlowe, 10 (pictured in August 2023)

The actress, who lives in New York and the UK, said at the time she wasn’t a big fan of the spin class SoulCycle. 

She said: ‘Sometimes I cringe a little bit at the motivational aspect of it, but that’s just because I’m English and we’re not used to saying, ‘You see your dream! Go get it”. 

‘Cooking is a focus for me,’ Sienna shared, ‘But I wouldn’t say healthy… I’m more of a home cook: roasts, some Asian food, pastas and sauces and soups. 

‘In terms of, like, chia seed and whatever grains, no. I’m like, ‘Fried eggs and Marmite toast’.’