Yellowstone fans have been left in a state of shock over Kelly Reilly’s real-life accent,

with many admitting they had ‘no idea’ that she was British.

The actress, 47, has been played Kevin Costner’s on-screen daughter Beth Dutton in the Paramount Network western since it premiered in 2018 and during that time has worked tirelessly with a dialect coach to perfect her Montana twang.

On Thursday, Kelly appeared on The Drew Barrymore Show where she surprised the host, 49, and audiences with her natural speaking voice.

‘I would have never guessed you had an accent!’ Drew exclaimed.

‘Well, that’s thanks to my dialect coach because she’s amazing, Jessica Drake,’ Kelly replied.

‘We were really going for a Montana accent, but she’s [Beth] educated. She’s from a very, very wealthy ranching family. I wasn’t going to go, like, “Howdy, ma’am.”

‘It wasn’t that for me.’

‘But I certainly wanted to get that Montana dialect correct,’ Kelly continued. ‘So, I worked with Jessica.

‘I’d worked with her on Flight and True Detective and all these other American accents I’d done.

‘But for Beth, it was more about the voice, because she smokes a little bit. She drinks a lot of bourbon.’

‘She has a rasp,’ Drew observed.

‘Like a guttural sound.’

‘I listened to Kevin a lot because he really deepened his voice for John Dutton, so I just stole it. I just copied him,’ Kelly added.

Like Drew, viewers at home were completely taken aback by Kelly’s normal accent.

Responding to a clip from the show which had been posted on the official TikTok page, one said: ‘My brain is fighting her voice/accent… it just isn’t registering that she doesn’t naturally speak like Beth.’

Another wrote: ‘I didn’t know she was English.’

Echoing a similar sentiment, someone else reacted: ‘This whole time I thought she was American. Wow, what can’t she do. I love Beth.’

‘MY BRAIN DOES NOT COMPUTE!’ a fourth exclaimed.

A fifth added: ‘I would never know she was British.’

Kelly has enthralled audiences playing the only daughter of Kevin Costner’s character Beth.

Born and raised in Chessington, London, Kelly attended Tolworth Girls’ School in Kingston, where she studied drama for GCSE under the watchful eye of her hospital receptionist mother and police officer father.

Before discovering her talent for acting, she loved working with horses and thought she’d have a future in equestrianism.

The actress first hit TV screens in 1995, starting her career in BBC Children’s drama series The Biz alongside former EastEnders star Paul Nicholls.

She also landed a role in 1995’s Prime Suspect 4: Inner Circle after getting her foot in the door by writing to the producers of the drama series.

As well as her roles in TV, Kelly managed to build up a name for herself in the theater world, working with Terry Johnson in four productions: Elton John’s Glasses (1997), The London Cuckolds (1998), The Graduate (2000) and Piano/Forte (2006).

At age 26, Kelly received a Laurence Olivier Theatre Award nomination in 2004, making her the youngest actor to receive such an honor after starring in After Miss Julie, a Michael Grandage production at the Donmar Warehouse in London’s West End in 2003.

She went on to play the role of Caroline Bingley in 2005’s Pride And Prejudice alongside Keira Knightley.

Her first leading role came in the 2008 horror film Eden Lake, starring alongside Hollywood heavyweight Michael Fassbender as a young couple terrorized by a group of murderous teenagers on a weekend away, earning herself a Best Actress nomination at the British Independent Film Awards

The following year, Kelly continued to keep her star profile alive with a role on primetime British series Above Suspicion, playing a rookie detective determined to prove herself in the male-dominated police department.

Hollywood soon beckoned for Kelly who starred in both 2009’s Sherlock Holmes and the 2011 sequel A Game of Shadows, playing Mary Watson.