Among the many recently launched spy-thriller series being produced by international OTT platforms is Slow Horses, probably one of the most highly anticipated releases in that genre.
The series delivers a gritty and humorous view of British intelligence through the dysfunctional oddballs of Slough House and their irascible head, Jackson Lamb. As fans look to Season 6, expectations are high for more high-stakes intrigue, betrayals, razor-sharp banter, and edge-of-your-seat espionage as the Slow Horses find themselves on the run in a deadly game of retaliation and revenge initiated by Diana Taverner, following the shocking twists and turns of Season 5 in 2025.
Slow Horses Season 6: Release Date Rumors
There has been no official announcement from Apple regarding the premiere of Season 6 of Apple TV+ as of March 2026. The show has been released nearly every year over the past few seasons, including:
• Season 4 (September/October 2024)
• Season 5 (September/October 2025)
Season 6 has recently completed filming and was shot back-to-back or around the same time as previous seasons (production wrapped earlier than normal). Most reports provide a likely release date in fall 2026 (typically September/October), so they'll continue releasing it nearly every year. There is some speculation that, due to having a shorter filming schedule, it could also be premiered earlier, such as during the summer or spring of 2026. However, the overall consensus is that they will follow their regular window for award season and stick with their current yearly release schedule. There may, however, be trailers or first footage dropped early 2026; if they haven't already. Updates on the premiere should be available soon, as we're currently in March.
Slow Horses Season 6: Cast News
The core cast is expected to return, with **Gary Oldman** confirmed to reprise his role as Jackson Lamb. Other key returning members likely include:
- Kristin Scott Thomas as Diana Taverner (now in a major leadership position at MI5 after Season 5 events)
- Jack Lowden as River Cartwright
- Saskia Reeves as Catherine Standish
- Rosalind Eleazar as Louisa Guy
- Christopher Chung as Roddy Ho
- Aimee-Ffion Edwards as Shirley Dander
- Ruth Bradley as Emma Flyte
- Tom Brooke as J.K. Coe
- Jonathan Pryce as David Cartwright (and potentially others like James Callis in recurring capacity)
No major new cast announcements have surfaced recently, but the ensemble remains largely intact. Note that head writer Will Smith departed after Season 5, with Gaby Chiappe leading Season 6 scripts-this could bring a slight tonal shift, though the show's signature dark humor and espionage style should persist.
Slow Horses Season 6: What to Expect (Plot and Teasers)
Elements from Mick Herron's books Joe Country (book 6) and Slough House (book 7) are incorporated into Season 6 alongside Diana Taverner, involving the Slow Horses in a "fatality high-stakes game of retaliation and revenge".
You may expect that the high intensity spy action, betrayals, and misfits of the team are being persecuted by MI5, enemies outside of MI5, and the fallout from within.
Key themes from the books and teasers:
- Targeted/their forced hiding.
- Previous events (i.e., people like Frank Harkness) needing revenge.
- IM5 is no longer chaotic under new leadership.
- Many twists and turns, including resurrecting dead people, assassinations, and the team being further marginalized.
More sharp wit, political intrigue, gritty action, and character drama. Production has already begun on Season 7 (late 2025 filming based on the book Bad Actors), so the series is still strong and now continuing!!
Keep up with Apple TV+'s announcements for more official news; however, some sources suggest a drop in 2026!. Seasons 1-5 are available to stream currently.