Season 6 of Slow Horses premieres on Apple TV on September 16, 2026. The six-episode run opens with one episode before continuing weekly through October 21.
The new season draws from Joe Country and Slough House, the sixth and seventh novels in Mick Herron's Slough House series. Gary Oldman is back as Jackson Lamb, leading the MI5 rejects who have made professional failure into a remarkably durable television franchise.
Slough House is on the run again
Season 6 puts Lamb's team in motion after Diana Taverner pulls them into a deadly cycle of retaliation and revenge. Kristin Scott Thomas returns alongside Jack Lowden, Saskia Reeves, Christopher Chung, Aimee-Ffion Edwards and Rosalind Eleazar.
The wider cast includes Joanna Scanlan, Samuel West, Ruth Bradley, Tom Brooke, Jonathan Pryce and Hugo Weaving, with Lenny Rush joining the series. Olivia Cooke also returns as Sidonie “Sid” Baker, bringing back a character with roots in the show's earliest episodes.
Season 8 is already official
Apple's longer-term commitment is the more striking part of the day's news. The company has ordered an eighth season even as Season 6 begins its public run.
Season 8 will consist of six episodes and adapt Clown Town, the ninth novel in Herron's Slough House series. Oldman will again lead the cast, with Kristin Scott Thomas, Jack Lowden and Olivia Cooke also attached.
That leaves Season 7 sitting between the episodes arriving now and a further season that is already confirmed. Streaming dramas rarely receive that much runway in advance, particularly this deep into their lifespan.
A production model built to keep moving
Slow Horses has one obvious advantage: compact seasons and a substantial literary backbone. Six-episode runs make the production cycle relatively contained, while Herron's novels provide Apple and See-Saw Films with established stories to adapt rather than forcing the series to reinvent itself every year.
Gaby Chiappe adapted Season 6 for television, with Adam Randall returning to direct. Executive producers include Jamie Laurenson, Hakan Kousetta, Julian Stevens, Iain Canning, Emile Sherman, Gail Mutrux, Douglas Urbanski and Oldman.
For a show about intelligence officers banished to a professional dead end, Slow Horses has ended up with a remarkably clear road ahead.
