Saoirse Ronan dresses down for a stroll with boyfriend Jack Lowden

She is set to star in the big-budget comedy Barbie, but Saoirse Ronan ditched the fashion doll look when she went for a romantic stroll with her actor boyfriend last week.

The Irish actress was dressed down as she took to the West London streets in a branded sweatshirt from Pleasing – the eco-friendly fashion label set up by her friend Harry Styles – tracksuit bottoms and well-worn trainers.

She and her partner Jack Lowden, star of the BBC’s War And Peace, were enjoying some downtime walking their terrier Fran before Saoirse starts filming the star-studded Hollywood blockbuster based on the Mattel doll.

In the movie, due out next year, she is reported to be playing an ‘alternative’ Barbie to the one played by star Margot Robbie. Boyfriend Ken will be played by Ryan Gosling, whom Saoirse has credited with getting Hollywood to pronounce her unusual Irish name correctly.

The pair have been dating for at least two years after meeting on the set of the 2018 movie Mary Queen of Scots, in which Saoirse played the title role and Lowden was her husband, Lord Darnley

Jack Lowden was recently seen out in London for the premiere of his new movie ‘Slow Horses’ with Gary Oldman on March 30

When he presented her with an award in 2015, Gosling told the audience, ‘It’s Ser-sha, like inertia’, and after that everyone was getting it right.

‘The power of Ryan Gosling is stronger than anything else,’ Ronan said a few months later, likening him to a ‘blond Canadian Jesus’ for his ability to spread the word.

Ryan Gosling has been credited with getting Hollywood to pronounce Saoirse Ronan’s name correctly.  Gosling told an audience: ‘It’s Ser-sha, like inertia’

During the relaxing walk in Notting Hill, close to where the couple live, Saoirse, 28, affectionately touched Lowden’s hand as he steered Fran along the leafy streets. The pair have been dating for at least two years after meeting on the set of the 2018 movie Mary Queen of Scots, in which Saoirse played the title role and Lowden was her husband, Lord Darnley.

The 31-year-old actor, who recently starred in Apple TV’s acclaimed thriller Slow Horses, isn’t the only object of Saoirse’s affections. She is reported to be besotted with her terrier, whom she named after a gangster character in the Irish TV drama Love/Hate.

‘Fran from Love/Hate is my favourite character and I love [actor] Peter Coonan in it. I’ve told him this and I called my Fran after him,’ she said.

‘Originally we wanted a boy dog and then we met Fran and we were like, “No, it’s only ever been you”. So she got the name. So technically she’s Frances, but she’s named after a drug dealer from inner-city Dublin.’