Foundation season 4: everything we know so far about the Apple TV+ show's return

Foundation season 4 is officially in development. And, with plenty more story left to cover from Isaac Asimov's 'Foundation' book series, it would be a huge shame if Apple's sci-fi epic had been canceled after three seasons.

So, what do we know about the Apple TV+ series' next outing? This guide is your one-stop shop to everything we know so far about Foundation's return. From next season's likely cast and where its plot could go, to my prediction about a plausible release date, here's the latest information about Foundation season 4.

Foundation season 4 release date speculation

Unsurprisingly, there's no confirmed launch date for the show's next 10-episode entry. However, Foundation season 4 was officially confirmed on September 11, so we know another installment is on the way.

Before that announcement, very few people knew if it would be back. Speaking to me in late June before season 3 debuted in mid-July, stars Jared Harris and Lou Llobell said they didn't know if Foundation would get a fourth season. Llobell and fellow actor Tómas Lemarquis provided another disappointing season 4 update ahead of last season's finale, too – the pair reconfirming they'd heard nothing about whether the series had been renewed.

That said, in February, Deadline indicated Foundation season 4 was in the works with a new showrunner, so it seemed to be a case of when, not if, it would be announced.

As for when season 4 could be released, that's difficult to predict. Development on seasons 1 and 3 was impacted by the pandemic and the 2023 Hollywood strikes, respectively, so they arrived later than anticipated.

On average, new seasons of Foundation take two years to make. And, even though principal photography is set to begin in early 2026, I don't expect it to air until mid- to late 2027.

Foundation season 4 trailer: is there one?

Unsurprisingly, a trailer isn't available. It'll be a long time until one is released, too, so don't expect this section to be updated for a while.

Foundation season 4 cast: who could return?

Full spoilers follow for Foundation season 3.

Based on how last season ended, here are the actors and the characters they play who I expect to see in Foundation season 4:

• Jared Harris as Hari Seldon
• Lou Llobell as Gaal Dornick
• Terrence Mann as Brother Darkness
• Synnøve Karlsen as Bayta Mallow/The Mule
• Cody Fern as Toran Mallow
• Brandon P Bell as Han Pritcher
• Alexander Siddig as Ebling Mis
• Tómas Lemarquis as Magnifico Giganticus
• Cherry Jones as Ambassador Quent
• Troy Kotsur as Preem Palver
• Rowena King as Kalle

The three biggest omissions from the above list are Lee Pace and Cassian Bilton, who played different iterations of Brother Day and Brother Dawn across the first three seasons, and Laura Birn, who portrayed Demerzel.

The trio has appeared in Foundation since it premiered in September 2021. However, with Demerzel being murdered by Brother Darkness in the season 3 finale, it's highly unlikely she'll return.

Pace and Bilton's futures are less clear than Birn's. Brother Darkness destroyed the lab that housed every other clone of the Galactic Empire's first (and long deceased) tyrannical ruler, Cleon I, so Pace and Bilton can't reprise their roles as new versions of Day and Dawn.

Meanwhile, the season 3 iteration of Day was killed by Brother Darkness in episode 10. After removing the self-healing nanites in his blood and the wristband-based aura shield that clones wear to protect them in episode 4, Day was no longer safe from harm. Long story short: he suffers a fatal shot to the chest from Darkness in the finale.

It's not impossible for Pace to return, though, because the season 3 iteration of Dawn is alive, albeit physically disabled following season 3's events.

If Foundation season 4 jumps forward in time and Dawn isn't killed off-screen between seasons, enough years could pass for him to age up and become Day, which would allow Pace to come back. However, if season 4 picks up in the immediate aftermath of its forebear, Bilton should reprise his role as Dawn, thereby meaning Pace won't be part of proceedings.

Like previous seasons, Foundation 4 could feature new characters. There are plenty more who have pivotal roles to play in the narrative tapestry woven through Asimov's works. Their introductions in the novels come much later in the story, though, so their inclusions are largely dependent on whether the aforementioned time skip is implemented.

Foundation season 4 story speculation

Full spoilers follow for Foundation season 3.

Predictably, Foundation season 4 doesn't have a logline or a more extensive plot synopsis.

We can still speculate on the direction its story could go next, though. I've already discussed large aspects of that in my Foundation season 3 ending explained piece, so I'd advise reading that before you proceed.

As I mentioned in the cast section, this season's narrative will largely depend on whether it picks up immediately after Foundation season 3's final episode.

Last season covered the second half of 'Foundation and Empire' and the first part of 'Second Foundation', aka the second and third novels in Asimov's original book trilogy. With the second half of the latter still needing adapting for Apple's retelling, I suspect Foundation 4 will take place directly after the events of last season's finale.

That's not the only book that season 4 could draw inspiration from. Two sequels – 'Foundation's Edge' and 'Foundation and Earth' – continue where the original trilogy left off. With season 3 episode 10, titled 'The Darkness', teasing elements of those novels in one of its final scenes, it's possible that some of their narrative threads could be woven into Foundation season 4.

Apple's live-action reimagining of Asimov's works will feature new plot strands as well.

At this point, Foundation has somewhat diverged from the overarching narrative played out in the source material. For example, in the novels, the Galactic Empire doesn't exist at this point in the timeline. However, season 3 ended with Brother Darkness not only going full autocrat and taking complete control of Empire, but also having a Death Star-style weapon – the black hole bomb – at his disposal. Under his monstrous command, Empire is clearly going to play an integral role in the space opera's plot.

"And what will Foundation season 4's story entail?", I hear you ask. Aside from the tyrannical threat posed by Empire to the entire galaxy, this season should primarily focus on The Mule's ongoing quest to locate The Second Foundation and Gaal's mission to stop Bayta – remember, Bayta Mallow was seemingly revealed to be The Mule in 'The Darkness' – for achieving her objective.

Of course, there are numerous other story beats that'll be explored next season. They include Quent joining The Second Foundation, what Hari Seldon's digital consciousness – he's referred to as Doctor Seldon, FYI – will do after being betrayed by Gaal, Brother Dawn's fate on the space station orbiting New Terminus, and whatever Kalle and her android allies are up to on planet Earth and its Moon. Expect plenty more twists and turns, then, if (and hopefully when) Foundation returns.

Will there be more seasons of Foundation?

That's hard to say. Originally, David S Goyer, the epic sci-fi show's co-creator, pitched an eight-season plan to Apple before it was commissioned by the tech giant's entertainment division. However, Goyer stepped down as Foundation's showrunner last February amid reported disagreements with the Apple hierarchy throughout season 3's development.

With a new showrunner coming on board for season 4, it doesn't sound like Goyer's eight-season plan is still being used. In a Q&A on his own website, Goyer claimed his outline was no longer being adhered to and that the show's creative team was charting its own path forward.

As I mentioned in the plot section, Apple's adaptation is only halfway through the story depicted in Asimov's 'Foundation' book trilogy and its two sequel novels, so there's still more narrative ground to cover. Still, given Goyer's comments and the likely expensive outlay of a series of this scope and scale, I wouldn't be shocked if Apple decides to wrap up Foundation's story with one or two more seasons.

For more Apple TV+ coverage, read our guides on Ted Lasso season 4, Presumed Innocent season 2, Severance season 3, and Silo season 3.