Colin Firth and two female cast members in The Staircase
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The Staircase: Full cast overview for thrilling new Sky drama starring Colin Firth and Toni Collette

Three episodes drop this week

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The Staircase starts on Sky Atlantic this Thursday (May 5), with Colin Firth and Toni Collette leading the cast.

Based on a true storyThe Staircase explores the life of Michael Peterson (Firth) and the suspicious death of his wife Kathleen (Collette).

Set in 2001, it’ll delve into their family life, Michael’s bisexuality and one of the longest trials in North Carolina history.

So, aside from the Hollywood pairing, who else is in the cast of the thrilling new drama?

Read on and we’ll tell you all we know!

Colin Firth and Toni Collette in The Staircase
Colin Firth and Toni Collette lead the cast in The Staircase (Credit: Sky)

The Staircase cast: Colin Firth plays Michael Peterson

Colin portrays as Michael Peterson, the man at the centre of a murder trial.

He served in the Marine Corps during the Vietnam War before living in Germany with first wife Patricia and their two sons.

During their time in Germany, family friend Elizabeth Ratliff was found dead at the bottom of her staircase, with her daughters Margaret and Martha left in Michael’s care.

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After his military career and his marriage ended, Peterson moved to North Caroline with his two children.

In 1997, Michael married Kathleen and they appeared happily married.

However, in 2001 Michael made a frantic call to 911 saying that he found his wife bloody and unconscious at the bottom of a staircase in their home.

He was ultimately charged and convicted of murdering Kathleen.

Michael is portrayed by British actor Colin Firth, an award-winning actor with a career spanning decades.

He shot to fame in the BBC adaptation of Price and Prejudice in 1995, playing Mr Darcy.

And he went on to star in many iconic film series including Bridget Jones, Mamma Mia! and Kingsman.

He also played King George VI in The King’s Speech, a role that saw him land an Oscar, a Golden Goose, a BAFTA and a SAG Award.

Toni Collette plays Kathleen Peterson

Kathleen’s death is the central mystery of the new Sky Atlantic series.

She earned a bachelors and masters degree from Duke University, where she was the first woman to be admitted to the engineering program.

Kathleen had one daughter from her first marriage.

Michael told police she fell down the staircase after mixing Valium with alcohol, but an autopsy revealed low doses of both in her system.

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The coroner found that Kathleen had sustained several wounds to the head and ruled she died hours after her initial fall from blood loss.

Though Michael was convicted of murdering Kathleen, he maintains his innocence to this day.

Toni Collette has been on stage and screen since the age of 14.

She starred in the title role in Murial’s Wedding, appeared in The Sixth Sense and from 2008 to 2011 played the lead in United States of Tara.

Toni has also appeared Knives Out, Little Miss Sunshine, About a Boy, In Her Shoes and horror film Hereditary.

She also led the cast in Netflix series Pieces Of Her.

Two girls looking scared in The Staircase
Odessa Young and Sophie Turner play Michael’s adopted daughters (Credit: Sky)

Sophie Turner plays Margaret Ratliff

The eldest of the Ratliff sisters, Margaret was taken in by Michael after losing both her parents at a young age.

They were adopted by him after her death and moved to North Carolina with him.

Her mother Elizabeth’s death was initially ruled to be the result of a brain haemorrhage, but possible foul play was called into question nearly 20 years later during Michael’s trial.

Sophie Turner, meanwhile is most well known for her role as Sansa Stark in Game of Thrones.

She also played a young Jean Gray in X-Men: Apocalypse and X-Men: Dark Phoenix.

Sophie is currently expecting her second baby with her husband Joe Jonas.

They’re already parents to daughter Willa, who is two this summer.

She’s also starred in a couple of Jonas Brothers videos.

Odessa Young plays Martha Ratliff

Australian actress Odessa Young portrays the youngest of the Ratliff sisters in The Staircase.

She’s starred in films including Assassination Nation and A Million Little Pieces and played Frannie Goldsmith in Stephen King’s The Stand.

The Staircase might just be the 24-year-old’s stand-out role, though.

Two men looking at a laptop in The Staircase
Actor Michael Stuhlbarg plays lawyer David Rudolph in the new show (Credit: Sky)

Michael Stuhlbarg plays David Rudolph

Michael Peterson’s lawyer David Rudolph is played by acclaimed actor Michael Stuhlbarg.

From day one he believed his client’s innocence and remained his lawyer for 15 years, even following the guilty verdict.

He helped Peterson pursue appeal attempts until he could no longer afford to pay him.

Stuhlbarg, meanwhile, is something of a crime drama veteran, so if he looks familiar, that’s because he is.

He also portrayed mob boss Jimmy Baxter in the brilliant Your Honor and lawyer Sy Feltz in Fargo.

He’s recently appeared in TV drama Dopesick with Michael Keaton and films including Call Me By Your Name and The Shape of Water.

Toy young men looking concerned in The Staircase
Patrick and Dane play Todd and Clayton Peterson in The Staircase (Credit: Sky)

Dane DeHaan as Clayton Peterson

Dane plays Michael’s son Clayton.

Along with his brother Todd and adopted sisters Martha and Margaret, he remains a staunch supporter of his dad and his innocence.

DeHaan made his on-screen debut when he appeared in an episode of Law & Order: Special Victims Unit in 2008.

He has since starred in a wide variety of filings playing characters including Harry Osborn in The Amazing Spider-Man 2 and Lucien Carr in Kill Your Darlings.

He’s got a big film coming up from director Christopher Nolan.

He’ll also appear in Oppenheimer, a biography about J Robert Oppenheimer, one of the physicists who worked on inventing the atomic bomb.

Patrick Schwarzenegger pays Todd Peterson

Arnie’s son Patrick plays Michael’s son Todd in the cast of The Staircase.

He’s been acting since he was 10, appearing as a young boy in the film The Benchwarmers.

He’s also been in Grown Ups 2, Midnight Sun and Moxie.

Family eating dinner in The Staircase
The show is based on the true story of Michael Peterson (Credit: Sky)

The Staircase cast: Olivia DeJonge as Caitlin

Caitlin is the daughter of the late Kathleen – a result of her first marriage to husband Fred.

At first she was on her stepdad’s side, but switched to become a key witness for the prosecution as the case progressed.

Olivia, meanwhile, played one of the two young co-leads in M Night Shyamalan’s The Visit.

She also starred in the Netflix series The Society.

After The Staircase, she’s off to star in the new Elvis Presley biopic.

It’ll be directed by Baz Luhrmann and she’ll play the singer’s wife Priscilla Presley.

Woman eating dinner in The Staircase
Rosemarie DeWitt plays Kathleen’s sister Candace in the series (Credit: Sky)

Rosemarie DeWitt as Candace Hunt Zamperini

DeWitt stars as Kathleen’s sister Candace.

She’s a central figure in the story and believes Michael killed her sister.

She ultimately played a key role in Michael being convicted of murder.

DeWitt is an acclaimed Hollywood actress.

She’s appeared in several films including La La Land and Poltergeist. More recently, she starred alongside Reese Witherspoon and Kerry Washington in Little Fires Everywhere.

She’s also been in Black Mirror, Mad Men, The United States of Tara and Cinderella Man.

Parker Posey looking stern in The Staircase
Parker Posey stars as (Credit: Sky)

Parker Posey as Freda Black

Lost in Space star Parker plays Assistant District Attorney Freda Black, prosecutor in the Michael Peterson murder trial.

She’s an acclaimed actress having starred in Waiting for Guffman, Best in Show, A Mighty Wind, Basquiat, The Daytrippers, Clockwatchers and Dazed and Confused, among many others.

She also appeared in New Girl, The Big C and The Good Wife.

The Staircase cast: Tim Guinee as Bill Peterson

Inventing Anna star Guinee plays Michael’s brother, Bill, an attorney.

Guinee’s extensive credits include Homeland, Hell On Wheels and Ramin Bahrain’s movie 99 Homes.

He can currently be seen leading the independent film Ash and appearing in Harriet with Cynthia Erivo.

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Where can I watch The Staircase?

The first three episodes of The Staircase will be available to watch on Sky Atlantic and NOW from 9pm on Thursday May 5.

There are eight episodes in The Staircase and the rest will be released weekly.

So will you be watching? Head to our Facebook page @EntertainmentDailyFix and tell us.


Nancy Brown
Associate Editor