Casualty breaking news — Olly Rix confirmed as Holby ED’s newest Clinical Lead

Following hot off the heels of the announcement that Robert Bathurst is joining Casualty as larger-than-life surgeon Russell Whitelaw, comes the news that Call the Midwife star Olly Rix is also making his debut on the BBC medical drama.

It’s been rumoured for months that Olly was filming in Cardiff, where Casualty is shot, and now BBC has officially confirmed his role on the show saying: “Olly Rix will play maverick Clinical Lead, Flynn Byron”.

Here’s everything you need to know about Olly’s new Casualty role…

Who is Olly Rix playing in Casualty?

Olly is playing a complex character with a troubled past when he joins Casualty as clinical lead Flynn Byron.

The new medic is expected to ruffle feathers as he takes over the prominent position from Acting Clinical Lead Siobhan McKenzie (Melanie Hill).

Siobhan has been filling in the role since former Clinical Lead Patrick Onley (played by Jamie Glover) left in disgrace. In recent on-screen episodes consultant Stevie Nash (Elinor Lawless) has been eyeing up the senior position and, knowing Stevie as we do, she may struggle to give him a warm welcome!

Olly Rix is best known for his roles in Agatha Raisin, Our Girl and, of course, Call The Midwife where he played Trixie Franklin’s (Helen George) husband, Matthew Aylward before the character moved to New York at the end of season 13.

Speaking about joining the medical drama Olly Rix says:

“It’s been a pleasure to join the Casualty cast in such a dynamic role. Flynn crashes into the world from a very different background, resulting in a complex and exciting story in Internal Affairs and beyond. It’s a brilliant new chapter for the show and I am excited for the audience to get to know Flynn.”

When does Olly Rix join Casualty

Olly Rix makes his onscreen debut on Casualty in March 2025. Keep an eye on our Casualty viewing guide where more information will be coming soon.

In today’s press release, the BBC said: “Olly is set to take on the role of charming but complicated Clinical Lead Flynn Byron and will first appear on screens from March in Casualty’s upcoming new miniseries Internal Affairs.

Roxanne Harvey, Executive Producer of Casualty for BBC Studios, adds: “Flynn’s journey promises to resonate with viewers, exploring the often emotional toll of working in the NHS, the cost of making tough decisions, and the possibility of redemption when you’re confronted with the consequences of your actions.”

Flynn’s military background

Like Casualty stalwart, paramedic Iain Dean and deceased fan-favourite Sam Nicholls (Charlotte Salt), Flynn comes from a military background. It remains to be seen if Flynn and Iain (Michael Stevenson) bond when they meet!

“Flynn Byron is a complex character driven by his past demons and the need to make his mark. As the new Clinical Lead Consultant at Holby City ED, Flynn joins the NHS fresh from a tour of duty. He’s a man with a purpose and a fierce resolve to make a difference. He faces the challenge of instilling change in a system weighed down by bureaucracy, all the while grappling with the trauma he has experienced and a deception that threatens to be his undoing.”

Flynn Bryon’s connection to Robert Bathurst’s Casualty character

In the announcement about Robert Bathurst, it was teased that his Casualty character, Russell Whitelaw would have major issues with his son-in-law Flynn!

BBC said: “Casualty‘s Internal Affairs explores the complexity of Russell’s character, particularly as his world is shaken by the arrival of his son-in-law, Flynn, a skilled army medic who becomes the victim of a tragic accident. As Russell saves Flynn’s life, he realises the young man has been unfaithful to his beloved daughter [Claire – actor TBA]. This discovery sets off a chain of events that forces Russell to confront his own sense of control – and whether his grip on power is truly as unshakable as he believes.”

New characters joining Casualty alongside Flynn

Flynn Byron doesn’t appear in Holby alone.

Elisabeth Hopper (Doctors, Ghosts, Home Fires) will star as the army medic’s wife, Claire Byron.

Sophie Melville (The Way, The Pact, Bang) will play his colleague Captain Amber Mitchell.

While Elsie Antonia Maurice and Lola Grace Maurice will star as Claire and Flynn’s daughters, Millie and Poppy.

Flynn’s introductory storyline

Flynn Byron is introduced in a special episode told from a patient’s point of view. It’s the story of a man involved in a road accident who is struggling to balance his family life and his military service – particularly in light of his affair with an officer who is severely injured in the crash. Adding to the intrigue is the revelation that Holby ED consultant Stevie Nash (Elinor Lawless) is in for a surprise when she recognises him!

When does Olly Rix make his Casualty debut?

Here at What to Watch we can wait to see how these new characters are introduced when the new 12-part Casualty chapter Internal Affairs premiers in on 15 March at 8.30pm on BBC1 and from 6am on BBC iPlayer.