Shetland Faces a Major Goodbye as Alison O’Donnell Confirms She Is Leaving Tosh Behind After 13 Years

One of Shetland’s longest-running characters is preparing to say goodbye.

Alison O’Donnell, who has played DI Alison “Tosh” McIntosh since the BBC crime drama began in 2013, has confirmed that she will leave the series after 13 years. Her final storyline will unfold during the upcoming six-part Series 11, bringing an end to a character who has been part of Shetland from its earliest days.

The BBC has said O’Donnell made the decision to depart so she could pursue other acting opportunities. Exactly how Tosh will leave has not been revealed, but executive producer Gaynor Holmes has promised the character will receive a farewell worthy of her long history with the drama.

And with Series 11 centered on an historic murder that will have lasting consequences for those connected to it, Tosh’s final investigation is set to arrive during another particularly significant chapter for the show.

Alison O’Donnell Says Playing Tosh Was “the Greatest Gift”

O’Donnell has been part of Shetland since its first series, when Douglas Henshall’s DI Jimmy Perez was still leading the investigations.

Reflecting on her departure, the actress described playing Tosh as “the greatest gift an actor could hope for,” saying that remaining with one character for so long had allowed her to explore Tosh’s development and maturity in a way few television roles permit.

She also paid tribute to the viewers who have remained invested in Tosh over the years and to the people she has worked alongside both in front of and behind the camera.

For O’Donnell, however, leaving Shetland means considerably more than finishing another acting job.

She said she had effectively grown up through the role, with the experience shaping her both as a performer and collaborator. The Shetland Isles themselves have also become a second home to her and her family after more than a decade connected to the production.

Although she acknowledged that walking away will be difficult, O’Donnell said she is looking forward to new adventures and taking everything she has learned from the series into the next stage of her career.

Tosh Has Been There Since the Beginning

O’Donnell’s departure carries particular weight because Tosh isn’t a later addition to the ensemble.

She was part of the original television cast when Shetland debuted in 2013, initially working alongside Jimmy Perez as the drama adapted the crime novels of award-winning Scottish author Ann Cleeves.

Over the following 13 years, Tosh grew from Perez’s junior colleague into an increasingly important investigator in her own right.

The series itself underwent a major transformation when Henshall departed after Series 7 in 2022. Ashley Jensen subsequently joined as DI Ruth Calder, beginning another era for the drama.

Rather than disappearing during that transition, Tosh became one of the show’s crucial links between its past and present.

Since Calder’s arrival, O’Donnell and Jensen have developed a new central detective partnership, allowing Shetland to continue after the loss of its original leading man.

Now the series is preparing for another major change.

The BBC Promises Tosh a Proper Farewell

The details surrounding Tosh’s departure remain deliberately under wraps.

There has been no official confirmation about whether she leaves the police, moves away from the islands or exits under entirely different circumstances.

What has been confirmed is that her departure will happen as part of Series 11.

BBC Drama executive producer Gaynor Holmes praised O’Donnell for bringing warmth to Tosh throughout her long run and said the production intends to give the character a “fitting farewell.”

Silverprint Pictures executive producer Kate Bartlett also described Tosh as a beloved character defined by empathy and warmth, while praising O’Donnell’s performances across the series.

That leaves viewers with a major unanswered question heading into the new episodes: what kind of ending is waiting for Tosh?

For now, the production isn’t giving that away.

Series 11 Begins With a Murder From the Past

Tosh’s final chapter will play out against another large-scale mystery.

The six new episodes revolve around an historic murder whose consequences reach into the present and are expected to permanently affect the lives of people connected to the case.

Filming began in Scotland and on the Shetland Isles in 2026, with Ashley Jensen returning as DI Ruth Calder alongside O’Donnell for Tosh’s final investigation.

Holmes has teased another story filled with twists and emotional stakes, something that now takes on additional significance knowing one of the drama’s longest-serving characters is approaching her final scenes.

But Calder and Tosh won’t be investigating alone.

Familiar Faces Are Returning

Series 11 will bring back several established members of the Shetland ensemble.

Steven Robertson returns as DC Sandy Wilson, while Lewis Howden is back as Sergeant Billy McCabe. His return is particularly noteworthy after Series 10 left questions hanging over his future.

Samuel Anderson reprises his role as Procurator Fiscal Matt Blake, with Steven Miller returning as Reverend Alan Calder and Anne Kidd as pathologist Cora McLean.

Angus Miller is also back as Tosh’s partner Donnie, while Conor McCarry returns as PC Alex Grant and Eubha Akilade as PC Lorna Burns.

Knowing that Donnie will be part of Tosh’s final series adds another personal dimension to whatever ending the writers have planned for her.

Series 11 Has an Extensive Guest Cast

The new mystery also brings another substantial group of actors to the islands.

Christine Bottomley, known for Sherwood, and Kevin Harvey from This City Is Ours have joined the guest cast, alongside The Crown actress Stella Gonet.

Scottish television veterans Gregor Fisher and Gavin Mitchell will also appear.

Additional guest performers include John Wark, Jude Bain, Robin Weaver, John McLarnon, Beth Marshall, Daniel Boyd, Charlene Boyd and Helen Mackay.

As with previous seasons, the ensemble will surround Calder and Tosh with a new network of characters whose connections to the central crime gradually emerge.

This time, however, the investigation carries another layer for longtime viewers: every episode brings Tosh closer to her departure.

O’Donnell Leaves After the Drama Survived One Huge Reinvention Already

Shetland has already demonstrated an unusual ability to survive major cast changes.

For seven series, Douglas Henshall’s Jimmy Perez was effectively the face of the programme.

His departure could easily have brought the drama to a natural conclusion. Instead, Ashley Jensen’s arrival as Ruth Calder gave the series a new central character while allowing established figures such as Tosh to carry its history forward.

O’Donnell has previously acknowledged that she initially worried about whether the reinvention would work.

Speaking about the transition, she recalled feeling emotional when she watched the first episode of the new era, partly from relief that the programme had successfully found a way forward.

The audience stayed with it.

In fact, Shetland remained one of the BBC’s strongest dramas. According to figures reported when O’Donnell’s departure was announced, it ranked among the BBC’s five most-watched drama series of 2025 and was the broadcaster’s No. 1 drama with audiences in Scotland.

The challenge after Series 11 will therefore be familiar but significant: reinventing the programme again after losing another character deeply associated with its identity.

Tosh Became One of Shetland’s Most Important Constants

Television detectives often change partners, but Tosh’s journey has been unusually long.

She worked alongside Perez through the original era and remained when Calder arrived to reshape the series.

That longevity gave viewers the opportunity to watch her evolve professionally and personally rather than remaining permanently frozen as a supporting detective.

It is exactly that gradual development that O’Donnell highlighted when announcing her departure.

Few actors get 13 years to inhabit the same character. Fewer still remain central to a series after its original lead has left.

Tosh managed both.

And that makes her impending goodbye more consequential than an ordinary cast departure.

How Tosh Leaves Remains the Biggest Mystery

The BBC has revealed the decision to leave but has carefully avoided revealing the circumstances surrounding Tosh’s final scenes.

That means viewers shouldn’t assume that the historic murder at the center of Series 11 necessarily determines her fate.

The only certainty is that O’Donnell’s final storyline takes place during the six new episodes and that the production intends to give Tosh an appropriate send-off.

After 13 years, there is plenty of history for the writers to draw upon.

There is Tosh’s career, her relationship with Donnie, her partnership with Calder and her deep connection to the islands.

Whatever ultimately takes her away from the series will close one of the longest-running character arcs in modern British crime television.

One Final Investigation for Calder and Tosh

For longtime viewers, Series 11 was already going to be significant.

A decades-spanning murder mystery, another major guest ensemble and the return of Calder and Tosh promised another atmospheric investigation against the Shetland landscape.

O’Donnell’s announcement changes the context completely.

Every scene between Calder and Tosh now carries the knowledge that their partnership has an ending.

Every development involving Donnie potentially carries additional significance.

And every step toward solving the historic murder also takes audiences closer to saying goodbye to a detective who has been part of the programme since 2013.

O’Donnell is leaving because she wants to explore new acting opportunities, and she has spoken warmly about both the production and the islands that became part of her life.

But for Shetland, her exit marks the end of another era.

Series 11 will air on BBC One and BBC iPlayer later in 2026. Series 1–10 are currently available on BBC iPlayer.