rocked four polar opposite looks while in New York on Wednesday.
The Pride and Prejudice actress, 37, was the picture of elegance as she stepped out in the Upper West Side of the city.
, who broke the story of the 1960s notorious serial killer, in the upcoming biographical drama.
For her first stop of the press day she donned an off-white two-piece with black accents on her belt and leather-studded heels .
She reversed the look completely for her second appearance in a stylish raven-black suit with a white shirt that tied in a chic bow by her neck.
Fashion parade: Keira Knightley rocked four polar opposite looks while promoting her new film Boston Strangler in New York on Wednesday
All in white: The actress donned a white ensemble with black detailing on the belt and shoes for her first appearances of the day
For both her looks the actress kept her make-up simple, emphasising her high cheekbones and sharp jawline, while keeping her brunette locks loose and straight apart from a slight wave near the ends.
For the third look, she slipped into a grey knitted jumper, teamed with a matching fur maxi skirt.
She boosted her height in a pair of black pointed toe heels with a silver bow detail to match her necklace.
And later in the day, for her fourth ensemble, the London, England native was a show-stopper in a tan overcoat adorned with a feathered design around the neck and touches down the front of the coat.
The actress also wore a pair shiny black shoes that went up past her ankles, and had her dark brown tresses styled long and chic down past her shoulders with a part on the slight left.
and her co-star Carrie Coon were dressed to the nines on Tuesday at a screening of their film the Boston Strangler at the Museum of Modern Art in New York.
The Pirates Of The Caribbean alum delivered goth glam as she posed for shutterbugs while The Gilded Age actress, 42, exuded elegance in head-to-toe beige.
Knightley stunned photographers as she arrived in a black puff-sleeve corset dress that highlighted her famously slender frame.
Raven-black: She turned her colour palette around completely, opting for a dark suit with white undershirt for her next stop in NYC
Class: The Pride and Prejudice actress was smart as she promoted her new film The Boston Strangler
Wow! For the third look, she slipped into a grey knitted jumper, teamed with a matching fur maxi skirt
Chic: She boosted her height in a pair of black pointed toe heels with a silver bow detail to match her necklace
Glowing: The two-time Oscar-nominated actress would also show off her infectious smile while making her way long the bustling streets of Manhattan
Excited: The Pride & Prejudice star also flashed her beaming smile while heading out later on Wednesday in her fourth striking look of the day
Classy: The London, England native was the picture of elegance in the tan overcoat with a feathered neckline that was matched with a pair of black shoes that came up past her ankles
Night on the town: The Love Actually actress would also mug for cameras before heading out for the evening
It was decked out with sequins that sparkled under the red carpet lights.
The mother-of-two stood on black platform heels and sported shiny ox blood nail polish.
The new release is written and directed by Matt Ruskin, while it also stars David Dastmalchian (The Suicide Squad, Dune), Chris Cooper, and Alessandro Nivola.
In real life, reporter Loretta passed away in 2018 at age 90. After uncovering the scandal, she went on to be an award-winning medical reporter and the second woman to serve as editor of the editorial pages at the Globe.
'This is a horrific story of the brutality of the male psyche and how disturbed and awful it can be, told through the eyes of two women,' Knightley recently said of the film.
'It's a tricky story to tell, because there are many different twists and turns.'
It comes after the actress said she put 'too much pressure on herself' and in the early years of her career.
Keira discussed navigating fame in a new interview with K and she will also star on the cover of the April issue.
On realising how much pressure she put on herself in the early years of her career, Keira said: ‘I was incredibly hard on myself. I was never good enough. I was utterly single-minded. I was so ambitious. I was so driven. I was always trying to get better and better and improve, which is an exhausting way to life your life.
'I am in awe of my 22-year-old self, because I’d like a bit more of her back. And it’s only by not being like that any longer that I realise how extraordinary it was. There was never an ounce of me that wasn’t going to find a way through.'
The London native rose to fame playing a tomboy footballer in the 2002 film Bend It Like Beckham.
Boston Strangler is slated for a Friday, March 17 release on Hulu.