There are currently five released series (seasons) of Slow Horses , with a sixth and seventh already confirmed and in development.

Quick Scoop

  • Seasons 1–4 are already available to stream on Apple TV+.
  • Season 5, also with six episodes like the earlier runs, began releasing in late 2025.
  • Apple TV+ has officially renewed the show for Season 6 and Season 7, so the total number of series will rise to seven once those air.

Extra context

  • The show adapts Mick Herron’s Slough House spy novels, generally using one book per TV series, which is why the episode counts stay tight and plot-heavy.
  • With eight novels published so far and more on the way, there is still plenty of material for future seasons beyond the currently confirmed seven, though nothing further has been officially ordered yet.

TL;DR: If you’re asking “how many series of Slow Horses are there?” as of early 2026, there are five you can watch now, with two more officially on the way.

Information gathered from public forums or data available on the internet and portrayed here.