Meet the cast of Six Four on ITV

Inspired by the bestselling novel of the same name by Hideo Yokoyama, the thriller series follows parents Chris (Kevin McKidd) and Michelle O’Neill (Vinette Robinson) as they struggle with their daughter's disappearance. But they're also faced with the infamous, unsolved case of another teenage girl some years prior which opens up a whole new world of criminal possibility.

McKidd is obviously known for his long-running role in Grey's Anatomy while Robinson has recently been on our screens in Boiling Point and The Gathering, so you just know this series is packed full of stellar performances from both.

This is a drama that certainly features plenty of twists and you never quite know which way it'll go but we do know it has a cast that boasts plenty of familiar faces too.

With that, read on for everything you need to know about the cast of Six Four.

Six Four cast: Full list of characters and actors in ITV drama

The full cast list for Six Four can be found below but scroll on to find out more about the characters, plus where you may have seen the actors previously.

• Kevin McKidd as Chris O'Neill
• Vinette Robinson as Michelle O'Neill
• James Cosmo as Jim Mackie
• Brian McCardie as Bill Martin
• Richard Coyle as Robert Wallace
• Alison Peebles as April Mclean
• Alex Ferns as Gordon Byrne
• Laura Cairns as Ms Fullerton
• Lorne Macfayden as Stuart Simpson
• Andrew Whipp as Philip O'Neill
• Iona Anderson as Annabel Wallace
• Frances Grey as Pauline Wallace
• Jessica Hardwick as PC McKenzie

Kevin McKidd plays Chris O'Neill

Who is Chris O'Neill? Chris is our complicated detective constable lead, who is struggling with the disappearance of his own daughter but seems to also be having a mid-life crisis of his own. His passion for his job is waning and his daughter's disappearance only puts pressure on his and Michelle's own relationship, but when he's confronted with a well-known unsolved case, his drive for his job starts to reignite. But will he be able to solve it?

Where have I seen Kevin McKidd before? McKidd is best known for his current recurring role in Grey's Anatomy, where he has played the role of doctor Owen Hunt for the past 14 seasons and also featured as a director. Aside from that, McKidd has starred as Tommy Mackenzie in Trainspotting, and has also had roles in Rome, Anna Karenina, Journeyman and has also voiced characters in Call of Duty: Modern Warfare video games.

Vinette Robinson plays Michelle O'Neill

Who is Michelle O'Neill? Michelle is a former undercover police officer who quickly takes matters into her own hands in regards to her daughter's disappearance. She uses her skills and previous contacts to try and uncover the truth, but runs into the criminal underworld she was previously involved in. As well as going through the heartbreak of her daughter's disappearance, Michelle is also dealing with her and Chris's current rough patch in their relationship.

Where have I seen Vinette Robinson before? Robinson has most recently received widespread critical acclaim for her role as Carly in Boiling Point, but has had numerous standout roles in Doctor Who as Rosa Parks and Sherlock as sergeant Sally Donovan, as well as starring in Black Mirror's 'Hated in the Nation' episode, Waterloo Road and The Lazarus Project, to name a few.

Andrew Whipp plays Philip O'Neill

Who is Philip O'Neill? Philip is Chris's older brother and is the assistant chief constable, making him a senior rank to Chris. It adds pressure to their already tense sibling relationship and he has nearly reached the top but isn't exactly where he wants to be, which only means Philip has a bit of a chip on his shoulder and is feeling increasing pressure from all sides.

Where have I seen Andrew Whipp before? Andrew is known for his role as Brian Fraser in Outlander and has also more recently starred in Shetland as Danny Cairns. He has also starred in Death in Paradise, The White Princess, Cursed, Vera and The Mallorca Files.

James Cosmo plays Jim Mackie

Who is Jim Mackie? Jim is the father of Julie, the local girl who has disappeared and the case that Chris is intent on revisiting. Jim is a former lawyer and politician so he's very smart but his daughter's unsolved disappearance had led to a staggering impact on his mental health. Speaking about his character in Six Four, Cosmo said: "He has just spiralled into this black hole of depression, anxiety and conspiracy theories. He has lost contact with most of the world."

Where have I seen James Cosmo before? The well-known Scottish actor is reunited with McKidd in this series after they both starred in Trainspotting in 1996. Among the many roles throughout Cosmo's career, he has notably starred in Game of Thrones, Highlander, Braveheart, The Chronicles of Narnia: The Lion, the Witch and the Wardrobe, His Dark Materials and Jack Ryan. He also finished fourth in Celebrity Big Brother season 19.

Brian McCardie plays Bill Martin

Who is Bill Martin? Bill is a police officer and someone who crosses paths with Chris later on in the series, as they're both searching for Jim Mackie. Bill worked on the original Julie Mackie disappearance case and is now someone who Jim blames for hiding the truth. Does Bill know more than he's letting on and will he stop Chris getting to the bottom of it all?

Where have I seen Brian McCardie before? McCardie has had numerous roles throughout his career, including more recently starring in BBC's Time alongside Stephen Graham and Sean Bean. He has starred in Taggart, Giri/Haji, Waterfront Beat and Line of Duty.

Richard Coyle plays Robert Wallace

Who is Robert Wallace? Robert is the justice minister and his daughter is suddenly kidnapped in the series. It's just as he's about to reach political election victory and it has similarities to the Mackie case, so the past could very well be repeating itself.

Where have I seen Richard Coyle before? Coyle starred in Steven Moffat sitcom Coupling as Jeff Murdock, but has also starred in Netflix's Chilling Adventures of Sabrina, The Fall and The Collection, as well as in numerous stage performances.

Alex Ferns plays Gordon Byrne

Who is Gordon Byrne? Gordon is another police officer who is initially investigating the disappearance of Annabel Wallace and is informed by the university's staff that she could've met someone "up the hill" late at night.

Where have I seen Alex Ferns before? Ferns is perhaps best known for his villainous role as Trevor Morgan in EastEnders, but has since starred in Chernobyl, which earned him a BAFTA Scotland award. He has also recently starred in The Batman, Andor, and The Devil's Hour, to name a few.

Six Four is available to stream on ITVX.

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