Slow Horses Season 6 Is Here: Release Date, Cast, Episodes & Everything to Know

Slow Horses Season 6 has arrived. The Apple TV+ spy thriller returns on September 16, 2026, with Gary Oldman back as the notoriously difficult Jackson Lamb and a six-episode story adapted from Mick Herron's Slough House novels. The new season opens with “Circle of Life” and will release one episode each week through October 21.

When Does Slow Horses Season 6 Start?

Slow Horses Season 6 premieres on Wednesday, September 16, 2026, on Apple TV+. The first episode arrives on premiere day, followed by one new episode every Wednesday through October 21.

The release date is now confirmed rather than an estimate. Apple TV announced the September 16 premiere in June and subsequently released the official Season 6 trailer in August. The sixth season contains six episodes in total.

Slow Horses Season 6 Episode Schedule

Season 6 follows the show's established weekly release pattern. The six-episode schedule runs from September 16 through October 21.

• Episode 1 — Circle of Life — September 16, 2026
• Episode 2 — September 23, 2026
• Episode 3 — September 30, 2026
• Episode 4 — October 7, 2026
• Episode 5 — October 14, 2026
• Episode 6 — October 21, 2026

The premiere episode, “Circle of Life,” begins with River Cartwright dealing with his grandfather's funeral while Jackson Lamb looks into the death of an ex-Slow Horse. The episode sets up the season's wider conflict without giving away later developments.

What Is Slow Horses Season 6 About?

Slow Horses follows a dysfunctional group of British intelligence agents who have been pushed into Slough House, the MI5 department used as a dumping ground for agents who have made career-ending mistakes.

Jackson Lamb leads the team, and despite the group's reputation, the Slow Horses repeatedly become involved in serious espionage cases. The series combines spy-thriller plotting with dark comedy and workplace friction.

Season 6 sees the Slow Horses caught up in a high-stakes conflict involving Diana Taverner. Apple TV describes the new story as one in which the team is on the run while Taverner becomes involved in a dangerous game of retaliation and revenge.

Slow Horses Season 6 Cast

The main ensemble returns for Season 6, with Gary Oldman again leading the cast as Jackson Lamb. Several familiar Slough House agents and MI5 figures are also back, while Lenny Rush joins the season as a new addition.

• Gary Oldman — Jackson Lamb
• Jack Lowden — River Cartwright
• Kristin Scott Thomas — Diana Taverner
• Saskia Reeves — Catherine Standish
• Rosalind Eleazar — Louisa Guy
• Christopher Chung — Roddy Ho
• Aimee-Ffion Edwards — Shirley Dander
• Joanna Scanlan — Moira Tregorian
• Samuel West — Peter Judd
• Jonathan Pryce — David Cartwright
• Hugo Weaving — Frank Harkness
• Ruth Bradley — Emma Flyte
• Tom Brooke — J.K. Coe
• Olivia Cooke — Sidonie “Sid” Baker
• Lenny Rush — New Season 6 Cast Member

Is Olivia Cooke Returning to Slow Horses?

Yes. Olivia Cooke returns as Sidonie “Sid” Baker in Season 6. Sid has been an important part of the wider Slow Horses story, and her return is one of the notable developments in the new season.

Apple TV confirmed Cooke's return ahead of the Season 6 premiere, including her in the first-look material released for the new season.

Who Is Jackson Lamb?

Jackson Lamb is the head of Slough House and the central character played by Gary Oldman. Lamb is an experienced intelligence officer whose abrasive personality and unconventional methods contrast sharply with the bureaucracy surrounding MI5.

Oldman's performance has become one of the defining elements of Slow Horses, while the character's relationship with River Cartwright and the rest of the Slough House team drives much of the show's interpersonal drama.

How Has Slow Horses Been Rated?

Slow Horses has built a strong critical record across its first five seasons. Rotten Tomatoes currently lists the overall series at a 98% average Tomatometer score from 224 critics' reviews, while every completed season is listed as Certified Fresh.

Season 6 currently has a 100% Tomatometer score based on 12 critics' reviews on Rotten Tomatoes. Because the season has only just premiered, that number can change as more reviews are added.

Where Can You Watch Slow Horses Season 6?

Slow Horses Season 6 is streaming on Apple TV+. The complete first five seasons are also available on the service, making it possible to catch up before watching the new episodes.

Season 6 is being released globally, with the premiere arriving on September 16 followed by weekly episodes through October 21.

Has Slow Horses Been Renewed for Season 7 and Season 8?

Yes. Slow Horses already has a seventh season in the pipeline, and Apple announced an eighth season on September 15, 2026, one day before Season 6 premiered.

Season 8 will be adapted from Mick Herron's Clown Town, the ninth novel in the Slough House book series. Apple has confirmed that Gary Oldman will continue to star as Jackson Lamb.

What Book Is Slow Horses Season 6 Based On?

Season 6 is adapted from Mick Herron's Joe Country and Slough House, the sixth and seventh novels in the Slough House series.

The television adaptation continues the show's approach of combining material from Herron's novels with its established ensemble and ongoing storylines.

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