Sienna Miller made sure all eyes were on her as she posed up a storm at the Marion premiere in Venice on Friday.

The actress, 42, showed off her ample cleavage as she wowed in a plunging black strappy gown.

Flashing plenty of skin in the ensemble, Sienna looked incredible as she matched the simple black ensemble with some stylish shades and a chunky silver necklace.

The mother-of-two, who welcomed her second child and first with boyfriend Oli Green back in December, looked to be enjoying a child free day as she was helped onto the boat.

The star seems to well and truly be in her ‘Siennaissance’ era as she continues to serve up her plethora of fashionable looks less than a year post-baby.

Sienna Miller, 42, hit the red carpet in an extreme plunging black gown which showed off her ample cleavage as her incredible post-baby ‘Siennaissance’ continues at Venice Festival on Friday

Flashing plenty of skin in the ensemble, Sienna looked incredible as she matched the simple black ensemble with some stylish shades and a chunky silver necklace

Sienna was last seen with her boyfriend, 27, last month as the pair enjoyed a romantic holiday together in Saint-Tropez.

The couple’s sunny trip comes after they welcomed their first child together, a daughter, in December 2023.

Sienna already has 12-year-old daughter Marlowe from her previous relationship with actor Tom Sturridge, 38.

Her new boyfriend, Oli, an actor who is 15 years her junior, is just like her — instinctive and a free spirit. In an interview earlier this year she explained: ‘I think you either live your life with caution or you take risks.’

She added that whatever success, or otherwise, her choices are met with, she is finally at peace.

‘For the longest time, I felt the need to really prove something, and I can see that reflected in the choices that I made. I pursued roles that were very heavy and very dramatic and challenging emotionally because I felt that I was probably seen as frivolous. I’m now completely over that.’

Sienna’s pregnancy was revealed during a exotic holiday in August last year, where she stepped out for a day at the beach and visibly showed off her blossoming bump.

She later appeared on the cover of Vogue, displaying her bare bump alongside both Marlowe and Oli, as she spoke about her pregnancy for the first time and revealed she was expecting another girl.

Two men helped steady the star as she headed onto the boat in her stunning dress

The mother-of-two, who welcomed her second child and first with boyfriend Oli Green back in December, looked to be enjoying a child free day as she was helped onto the boat

The star seems to well and truly be in her ‘Siennaissance’ era as she continues to serve up her plethora of fashionable looks less than a year post-baby

She completed her look with some simple black heels

Sienna’s pregnancy was revealed during a exotic holiday in August last year, where she stepped out for a day at the beach and visibly showed off her blossoming bump

Sienna made sure to turn heads for her debut at this year’s Venice Festival

During the rare interview, the Horizon: An American Saga star spoke candidly about how her pregnancy had been ‘unplanned’.

But she added that Marlowe had been wanting a sibling for some time and admitted she felt ‘more psychologically prepared’ than with her firstborn.

Sienna said: ‘I was very fortunate. I wasn’t necessarily trying to get pregnant. This happened as a total surprise and biologically was something I was able to do.’

Discussing what is different this time around, she explained: ‘I have expectations where I had none before. I feel much more psychologically prepared than I was with Marlowe.

‘It was quite a shock, the reality. I hadn’t given it the thought, I guess you can’t prepare for it. In my mind I imagine it’s going to be the loveliest, but I think I’ve forgotten.’

Sienna went on to address the stigma around pregnancy as an older woman, confessing she’d been fighting her own prejudices around the subject.

She said: ‘I think people are comfortable with a way of living that has existed for many years, which is very misogynistic and patriarchal.

‘Like me being the older woman in a partnership with a younger person or being pregnant over 40 and that that’s irresponsible and poor child and it’s such double standards.’

She added: ‘I’d love to get to a point where I didn’t feel the need to make a joke of my being older and having a baby, to show I’m in on the joke.’