Season 4 of Apple TV+'s Foundation has finished filming, but Apple has said very little about it. Most of what circulates online is either a guess or a repeat of Season 3's cast list. This page separates three things: what Apple has confirmed, what comes from press reports, and what is still unknown. It was last checked on October 25, 2026, and I will update it when real news arrives. The update log at the bottom shows what has changed.
Confirmed by Apple
Apple announced the renewal in a press release dated September 11, 2025, the day before the Season 3 finale. It says:
- Ian Goldberg and David Kob are co-showrunners and executive producers for Season 4, alongside Bill Bost, Lee Pace, Michael Satrazemis, Robyn Asimov, and David S. Goyer.
- Production was set to begin in early 2026.
That is the whole of it. The release names no Season 4 cast, gives no episode count, and gives no premiere date. It does list Season 3's cast, including Jared Harris, Lee Pace, Lou Llobell, Laura Birn, Terrence Mann, Cassian Bilton, and Pilou Asbæk, but as the cast of the season that was airing, not as a Season 4 lineup. For how the showrunner change came about, see why David S. Goyer left.
Reported, but not announced by Apple
These details come from press coverage, so treat them accordingly.
Production
- Filming began on January 5, 2026, in Prague, with more than 120 shooting days planned. According to The Prague Reporter, the schedule ran through July 11.
- Unlike earlier seasons, which were split between countries, Season 4 was shot entirely in the Czech Republic. Locations named in that report include Prague Studios in Letňany, Troja Palace, Libochovice Castle, underground water tanks in Brno, and the former Poldi industrial site in Kladno.
- Screen Rant reported on September 10, 2026, that Lee Pace wrapped filming in July.
Cast
- Lee Pace, whose Brother Day was killed in the Season 3 finale, is working on the season. Screen Rant says his presence in the story is not over, and he has described the season as one that "gets bigger."
- Cherry Jones is reported to return as Ambassador Quent in a seven-episode recurring role.
- The Prague Reporter names Jared Harris and Lou Llobell among the returning cast.
- No full Season 4 cast list has been published.
Story
- The Prague Reporter says the season picks up directly from the Season 3 finale with no significant time jump. This comes from a single source, and Apple has not confirmed it.
Still unknown
- Premiere date. Apple has not announced one. Coverage points to 2027, and The Prague Reporter calls mid-2027 the most probable window, but that is the outlet's own estimate. Screen Rant says only that the series is eyeing 2027.
- Episode count.
- Roles for most of the cast, including which Season 3 characters survive into Season 4.
- Any specific plot beyond the Season 3 finale.
Where Season 3 left things
These threads are facts from the finale, not predictions. For the full episode-by-episode account, see the Season 3 guide.
- The Mule. Gaal kills a man she believes is the Mule, then learns he was a puppet and the real Mule is Bayta Mallow. Gaal escapes the Mule's station when Magnifico's music overwhelms Bayta.
- The Cleons. Brother Dusk destroys the chamber of future clones, sparing only one infant, murders Brother Day, and declares himself Brother Darkness. Demerzel dies trying to save the infant.
- The Second Foundation. After Demerzel's final instructions, Ambassador Quent brings a book to the Imperial Library, where Preem Palver welcomes her into a Second Foundation now hiding on Trantor.
- The robots. A robot head recovered from Mycogen sends a signal across the galaxy, received by Kalle, who is hiding with other robots on Earth's Moon.
That last thread echoes the end of Asimov's Foundation and Earth, where Trevize finds R. Daneel Olivaw on Earth's Moon. Whether Season 4 follows that echo is not something anyone has confirmed. For the book side of the story, see our guide to Foundation and Earth and the reading order guide.
What to Watch For, Depending on How You Came to Foundation
Season 4 will land differently depending on whether you know the show, the books, or both. The points below are what to keep in view, not predictions.
If you have only watched the show. Season 3 pulled elements from three different novels. The Mule and Kalgan come from Foundation and Empire, the Second Foundation hiding on Trantor comes from Second Foundation, and the robot on Earth's Moon comes from Foundation and Earth. Reading even the original trilogy makes the show's choices easier to judge, because you can see which ones are Asimov's and which are the writers'. The reading order guide lays out both ways to approach the books, and the Season 3 guide recaps the finale episode by episode.
If you have read the books. Season 3 reversed the novel's central twist: the show's Mule is Bayta Mallow, where the book's Bayta is the one person who sees through him. That makes the show's own continuity the thing to track in Season 4, not the novels'. Useful points of comparison, if the show goes there, are how the Mule's story ends (in Second Foundation, the First Speaker adjusts his mind and he rules peacefully until he dies), and how the Second Foundation's hiding place on Trantor is revealed. Our Season 3 review explains why the changes divided readers.
For everyone. Because Apple has not announced a premiere date or a cast list, anything described as "confirmed" on other sites before then is worth checking against the sources above.
How to use this page
If you read a Season 4 "cast list" or "plot synopsis" elsewhere, check whether it comes from Apple or from a fan wiki. As of October 25, 2026, Apple has published none of those details. I will add confirmed information here as soon as it exists, and note the date of each update.
Frequently Asked Questions
Is Foundation Season 4 confirmed? Yes. Apple announced the renewal on September 11, 2025, and filming took place in Prague in 2026.
When does Foundation Season 4 come out? Apple has not announced a premiere date. Coverage points to 2027, but no outlet has an official date.
Who is in the Season 4 cast? Apple has not published a Season 4 cast list. Press reports name Jared Harris, Lou Llobell, and Cherry Jones as returning, and say Lee Pace worked on the season, but these are reports, not announcements.
Who is running Season 4? Ian Goldberg and David Kob are co-showrunners. David S. Goyer is no longer the lead creative force; see why he left.
Where was Season 4 filmed? Reportedly entirely in the Czech Republic, with Prague as the base.
Is there a trailer? As of October 25, 2026, I have not found an official trailer.
Update Log
- October 25, 2026: Rechecked Apple's announcements and the main press coverage. Nothing new has been confirmed since the last check: still no premiere date, episode count, or official cast list.
- October 19, 2026: Page published.