Season 4 of The Diplomat is confirmed, and we’ve got the latest on the release window, returning cast, and every major update so far.
Netflix’s tense, fast-talking political thriller The Diplomat is officially coming back for Season 4 – and that’s great news for anyone who likes their international crises paired with relationship sabotage and the occasional career-ending headline.
The show has had momentum from the start: after premiering on April 20, 2023, The Diplomat debuted at No. 1 on Netflix’s weekly global Top 10 TV (English) list, racking up 57.48 million hours viewed in its first weekend and landing in the Top 10 across dozens of countries.
So what’s next for Kate Wyler and when can we actually watch Season 4?
The Diplomat Season 4 | Release Date
Season 4 is confirmed, but Netflix hasn’t announced an official premiere date yet. The streamer renewed The Diplomat for Season 4 on May 14, 2025, and later confirmed that production would begin in fall 2025.
With that timeline, the realistic expectation is a 2026 release window – but until Netflix drops a date, consider that an estimate rather than a promise. The moment we get a trailer or a “coming on…” month, we’ll have a much clearer picture.
The Diplomat Season 4 | New & Returning Cast
At the center of it all, Keri Russell is expected to return as U.S. diplomat Kate Wyler, with Rufus Sewell back as Hal Wyler. The biggest headline for Season 4, though: Allison Janney (President Grace Penn) and Bradley Whitford (First Gentleman Todd Penn) have been promoted to series regulars, meaning the Penns are no longer a “special guest” complication – they’re part of the core engine.
Netflix hasn’t released a full official Season 4 cast list yet, but these are the main names you can reasonably expect to see again based on where the story is headed:
- Keri Russell as Kate Wyler
- Rufus Sewell as Hal Wyler
- Allison Janney as Grace Penn
- Bradley Whitford as Todd Penn
- David Gyasi as Austin Dennison
- Ali Ahn as Eidra Park
- Ato Essandoh as Stuart Hayford
- Rory Kinnear as Nicol Trowbridge
- Nana Mensah as Billie Appiah
As always with Netflix, additional returning characters and any new additions may be announced closer to filming or right before the season’s marketing push kicks in.
The Diplomat Season 4 | What Do We Know About the Plot?
Spoiler warning for Season 2 and Season 3: Season 4 is set up to be the show’s most dangerous political balancing act yet, because the story is no longer just about Kate surviving London – it’s about Kate being pulled into the gravitational field of the White House.
Season 2 ends with a full-blown constitutional crisis: President Rayburn dies, and Grace Penn is sworn in – a development that instantly turns every private conversation into a national security issue. Season 3 leans into that shift hard, dragging Kate and Hal closer to presidential power than either of them can safely handle, while the U.K. side remains volatile and personal alliances keep turning into leverage.
That’s the Season 4 hook in a nutshell: Kate doesn’t just have enemies now, she has proximity. With Grace Penn in charge and Todd Penn firmly in the picture, the Penns become a constant variable in Kate’s day-to-day survival, and Hal’s role in the chaos only raises the stakes. Expect Season 4 to double down on the show’s favorite question: is Kate making moves… or being maneuvered?
We don’t have official plot summaries yet, but with production slated for fall 2025, it shouldn’t be long before Netflix starts teasing where the next crisis lands and which relationship gets torched to contain it.
We'll make sure to keep you posted, don't you worry!