Slow Horses Season 6 premieres Wednesday, September 16, 2026, on Apple TV. The six episodes arrive weekly through October 21. Gary Oldman returns as Jackson Lamb, Olivia Cooke is back as Sid Baker, and the new story sends Slough House on the run after Diana Taverner pulls the team into a deadly cycle of revenge.
The season adapts two Mick Herron novels, Joe Country and Slough House. Apple has not released episode titles or runtimes, but it has already ordered a seventh season.
When does Slow Horses Season 6 premiere?
Episode 1 arrives globally on Apple TV on September 16. New episodes follow every Wednesday. This is a weekly release, so the full season will not be available on premiere day.
Slow Horses is also included in our September 2026 streaming guide, alongside the month’s other major movies and shows.
What is the full episode schedule?
- Episode 1 — 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
Apple has not announced the episode titles. The streaming service also has not given a universal release time, so the exact hour may vary by country and device.
What is Slow Horses Season 6 about?
Slough House is MI5’s dumping ground for agents whose careers have gone wrong. Jackson Lamb leads the group with bad manners, sharp instincts, and very little interest in following the polished rules of headquarters.
Season 6 puts the whole team in danger. Apple says the Slow Horses go on the run while Diana Taverner draws them into a fight driven by retaliation and revenge. The trailer shows Lamb and River Cartwright moving through damaged buildings, armed confrontations, and a funeral, but it does not identify who dies or who is hunting the team.
The official footage also warns that not everyone may make it out of Slough House alive. That could be a literal threat to the team or the end of the department as they know it. Apple has kept the answer out of the synopsis.
Why is Sid Baker back?
Olivia Cooke returns as Sidonie “Sid” Baker after the series left her fate open in Season 1. Apple has confirmed the return but has not explained where Sid has been, who knew she was alive, or whether she is coming back to help River.
Her return is one of the season’s biggest unanswered questions. Sid and River worked closely before she disappeared, and bringing her back during a story about old scores gives their reunion plenty to untangle.
Who is in the Slow Horses Season 6 cast?
- Gary Oldman as Jackson Lamb
- Jack Lowden as River Cartwright
- Kristin Scott Thomas as Diana Taverner
- Saskia Reeves as Catherine Standish
- Olivia Cooke as Sidonie “Sid” Baker
- Christopher Chung as Roddy Ho
- Aimee-Ffion Edwards as Shirley Dander
- Rosalind Eleazar as Louisa Guy
Jonathan Pryce and Hugo Weaving also return, while Lenny Rush joins the cast. Apple has not revealed Rush’s character.
Which books does Season 6 adapt?
Season 6 draws from Joe Country and Slough House, the sixth and seventh books in Mick Herron’s series. Using two novels does not mean each one will receive three episodes. The show has moved characters and events before, and Apple has not described how the material is divided.
Readers should also expect changes around Sid. The television series has handled her story differently from the books, so her return cannot be mapped cleanly from one chapter or plotline.
Is Slow Horses Season 7 confirmed?
Yes. Apple ordered a six-episode seventh season in July 2025. It will adapt Bad Actors, the eighth Slough House novel. Gary Oldman is confirmed to continue as Jackson Lamb, but Apple has not announced the Season 7 release date or full cast.
To watch Season 6, viewers need an Apple TV subscription. The service’s latest U.S. price is covered in our Apple TV price guide. The first five seasons are already available, and Season 6 begins September 16.
