The Slow Horses are galloping back to the small screen — and they’re bringing fresh blood with them. Apple TV has confirmed the hit TV series, which follows a group of misfit MI5 agents demoted to the Gary Oldman-governed Slough House, is set to return to the streamer on Sept. 16. The six-episode season will drop once-weekly on Wednesdays through Oct. 21. Here’s everything you need to know about the release date, new cast member Lenny Rush, plot, and more.
Slow Horses Season 6 Release Date — When and Where to Watch
Apple TV has confirmed Slow Horses season 6 begins on September 16, 2026. New installments of the season, which lasts for six episodes, will be released every Wednesday until its finale on October 21, 2026. Unlike some streaming services that drop full seasons at once, Apple TV+ is sticking with its weekly release format.
Release Details at a Glance
| Detail | Information |
|---|---|
| Series Title | Slow Horses |
| Season | Season 6 |
| Premiere Date | September 16, 2026 |
| Finale Date | October 21, 2026 |
| Total Episodes | 6 |
| Release Schedule | Weekly on Wednesdays |
| OTT Platform | Apple TV+ |
| Based On | Mick Herron’s novels “Joe Country” & “Slough House” |
What the First Look Reveals
Apple TV has released the first images from the upcoming season, offering glimpses of the returning cast and newcomer Lenny Rush. Also featured in the photos released this week are Kristin Scott Thomas, Tom Brooke, Aimee-Ffion Edwards, Lenny Rush and Christopher Chung. One particularly intriguing image shows Rush alongside Christopher Chung’s Roddy Ho, hinting at a possible storyline connection between the two characters.
Lenny Rush Joins the Cast
The biggest casting news is the addition of BAFTA TV Award winner Lenny Rush to the ensemble. Joining the series this season is BAFTA TV Award winner Lenny Rush. Rush, known for his roles in Doctor Who Season 14 (where he played UNIT scientific advisor Morris Gibbons), Am I Being Unreasonable, and Enola Holmes 2, brings fresh energy to the Slough House team.
She confirmed that Lenny Rush, who plays Ollie in the series and portrayed UNIT scientific advisor Morris Gibbons in Doctor Who season 14, had begun filming the sixth season when speaking with co-creator Daisy May Cooper for a Q&A for her returning series (via RadioTimes.com).
Lenny Rush Profile
| Detail | Information |
|---|---|
| Name | Lenny Rush |
| Award | BAFTA TV Award winner |
| Notable Roles | Doctor Who (Morris Gibbons), Am I Being Unreasonable (Ollie), Enola Holmes 2 |
| Slow Horses Role | New cast member (character details TBA) |
Season 6 Plot — On the Run
Season 6, which is based on Mick Herron’s sixth and seventh novels “Joe Country” and “Slough House,” will see MI5 boss Diana Taverner (Kristin Scott Thomas) embroil the Slow Horses in a “fatally high-stakes game of retaliation and revenge” resulting in them having to go on the run.
This marks the first time the series has adapted two novels in a single season, suggesting a more ambitious and complex storyline than previous installments.
Full Cast — Returning & New Members
Main Cast
| Actor | Character |
|---|---|
| Gary Oldman | Jackson Lamb |
| Kristin Scott Thomas | Diana Taverner |
| Jack Lowden | River Cartwright |
| Saskia Reeves | Catherine Standish |
| Christopher Chung | Roddy Ho |
| Aimee-Ffion Edwards | Shirley Dander |
| Rosalind Eleazar | Louisa Guy |
| Tom Brooke | J.K. Coe |
| Joanna Scanlan | Moira Tregorian |
| Samuel West | Peter Judd |
| Ruth Bradley | Emma Flyte |
| Jonathan Pryce | David Cartwright |
| Hugo Weaving | Frank Harkness |
| Lenny Rush | New addition (character TBA) |
Behind the Camera — Major Creative Shift
Will Smith, the original showrunner, steps down after Season 5, with Gaby Chiappe taking over as head writer for Season 6, while Adam Randall returns to direct. Chiappe, who served as co-executive producer on the series, is already a known quantity within the show’s creative world.
| Role | Name |
|---|---|
| Head Writer (Season 6) | Gaby Chiappe |
| Previous Showrunner | Will Smith (Seasons 1-5) |
| Director | Adam Randall (Emmy winner) |
| Production | See-Saw Films |
| Executive Producers | Jamie Laurenson, Hakan Kousetta, Julian Stevens, Gary Oldman |
The Slow Horses Phenomenon
Since its debut, SLOW HORSES has become one of Apple TV+’s most acclaimed original series, earning praise from critics and audiences alike for its sharp writing, dark humor, and standout performances. All five previous seasons hold Certified Fresh ratings on Rotten Tomatoes, with multiple seasons earning perfect critics’ scores.
The show has racked up serious awards attention since its first season, earning numerous BAFTA and Emmy nominations, including recognition for Oldman, Christopher Chung, Jonathan Pryce, and Jack Lowden. Director Adam Randall also took home the Emmy for directing for a drama series.
Season 7 Already Confirmed
The good news for fans: this isn’t the end. Apple TV+ has also officially ordered a seventh season of ‘Slow Horses’, ensuring the story will continue well beyond this autumn’s return. Slow Horses season 7 began filming in October 2025, with the show expected to return once more to Apple TV in 2027. Season 7 will be based on Bad Actors, the second-to-last novel in Herron’s series as of writing.
