The slow horses series is one of the most anticipated spy thrillers available on every major global OTT platform. This show provides a sharp, cynical view of how British secret service operates through its host of dysfunctional misfits at slough house, all under the command of the hot-headed and irascible Jackson lamb.
Season 6 promises to continue all of these themes and provide even more high-stakes espionage intrigue, biting wit and humour, betrayal and revenge than season 5 did, which had so many shocking moments that created severe emotional consequences for many of the characters.
Slow Horses Season 6 Release Date Speculations
In October 2024, Apple TV+ announced the renewal of Slow Horses for a sixth season, just after the final episode of Season 4 aired. The renewal confirmation is part of Apple’s larger plan to commit long-term to this outstanding espionage drama series. Slow Horses was also given the green light for a seventh season, further expanding the Slough House universe created by Mick Herron on-screen.
As for the release date of Season 6, it has not yet been announced. The only indications to date as to when Season 6 might premiere can be found by looking at the filming for Season 6 which wrapped in Spring 2025 per Gary Oldman. The pattern so far for the premieres of Seasons four and five (Seasons 4 will be released in September 2024 and Season 5 will air in October 2025) indicates that the release date for Season 6 will be in the Fall of 2026 (possibly September 2026). Some has speculated that Season 6 could release earlier (mid 2026), based on previous post-production timelines, however this has not been confirmed. It is expected Season 6 will release in 2026, Apple TV+ will probably release each episode weekly.
Slow Horses Season 6 Expected Cast
The main cast is supposed to come back: Gary Oldman (Jackson Lamb), Jack Lowden (River Cartwright), and Kristin Scott Thomas (Diana Taverner) and Saskia Reeves (Catherine Standish) as members of that main cast also returning. Other familiar faces likely returning would be: Rosalind Eleazar (Louisa Guy), Christopher Chung (Roddy Ho), Aimee-Ffion Edwards (Shirley Dander), Ruth Bradley (Emma Flyte), Tom Brooke (JK Coe) and Samuel West (Peter Judd) among many others.
Jonathan Pryce will probably be returning to play David Cartwright, giving continuity to River’s character arc. While there have been no official announcements concerning new casting, given that the adaptation of the two books is going to require a lot of expansion in terms of who River interacts. Reports are indicating that production of Season 7 began sometime in late 2025 and will continue with considerable continuity between the seasons.
Slow Horses Season 6 Potential Plot
The upcoming 6th season of Apple TV+’s Slow Horses sees the titular characters on the lam, as Diana Taverner embroils them in a dangerous game of retribution and payback. It is based on the novels Joe Country and Slough House, and has a larger scope than its predecessors; with political consequences, unresolved vendettas, and the long-term effects of decisions made in prior seasons all coming into play.
Details on the plot for Slow Horses Season 6 are yet to be revealed; however, fans of the series should expect storylines involving off-the-radar operations, divisions within Britain’s intelligence services, and increased personal stakes for the Slough House crew; River Cartwright’s family is likely to remain an important emotional element, while Jackson Lamb’s leadership style may reach the limit as his charges confront increasing threats to their person. With the unique nature of merging the two books into the first season to form a single-continuous narrative, the density of the Season 6 narrative structure is likely to differ from that of the previous five, offering multiple intertwining story arcs rather than focusing solely on one single mission.
Slow Horses Season 6 will stream on Apple TV+ on December 22, 2026; a preview of prior seasons and teasers for Season 6 will be released sometime between now and December 22, 2026.