'The Diplomat' Season 3 Promoted to Mid-October Debut

For a series that bills itself as a political drama and hails from former The West Wing and Homeland scribe Debora Cahn, The Diplomat sure loves to go for the most enormous cliffhanger swings imaginable. Season 1 ended with an assassination attempt that left multiple characters' fates uncertain right after revealing the "terrorist attack" was planned and executed by the British PM; Season 2 ended with the death of the American President of the United States, creating a succession crisis as the current Vice President is promoted and now has her old position as a plum offering for those who will do her bidding.

All this and a hilarious portrait of a toxic marriage between two people who love to hate each other... or hate to love each other? The series' anti-hero, American Ambassador to the U.K., Kate Wyle, and her British husband (and former diplomat), Hal, are two characters who are twisted creatures of the political system, willing to stay yoked together for the sake of their own chances at rising through the ranks. They probably need each other, unless, of course, their own ambitions blind them to how much they're really not helping each other at all.

The Diplomat was a sleeper hit for Netflix when it first debuted in the spring of 2023 and drew a much larger viewership with Season 2 when it premiered on Halloween weekend 2024. Season 3 will also aim for an autumn premiere, arriving on the service a little earlier, in mid-October. Check out the Date Announcement teaser.

Here's the Season 3 synopsis:

The consequences of Season 2’s explosive finale begin to unravel, with tensions running high amongst all parties, both within the halls of the White House and across the pond. In Season 3, Ambassador Kate Wyler lives the particular nightmare of getting what you want. She just accused Vice President Grace Penn of hatching a terrorist plot and admitted she’s after the VP’s job. 

But now the President is dead, Kate’s husband Hal may have inadvertently killed him, and Grace Penn is the leader of the free world. None of this slows Hal’s campaign to land Kate the vice presidency. Kate steps into a role she never wanted, with a freedom she never expected, an increasingly complicated friendship with Foreign Secretary Austin Dennison, and an unnerving bond with First Gentleman Todd Penn.

Keri Russell (The Americans) once again returns as Kate Wyle, with British actor Rufus Sewell (Victoria) as her remarkably ambitious husband, Hal. American actor Allison Janney returns as now-President Grace Penn, and Bradley Whitford (The Handmaid's Tale) joins the cast as her husband and First Gentleman, Todd Penn.  

The ensemble also includes British actor David Gyasi (The Sandman) as U.K. Foreign Secretary Austin Dennison, and Rory Kinnear (Ridley Road) as British Prime Minister Nicol Trowbridge, plus Americans Ali Ahn (Agatha All Along) as CIA station chief Eidra Park, Nana Mensah (Elementary) as White House chief of staff Billie Appiah, Michael McKean (Good Omens) as the late POTUS William Rayburn, Miguel Sandoval (Dirk Gently's Holistic Detective Agency) as U.S. Secretary of State Miguel Ganon, and Ato Essandoh (Altered Carbon) as Stuart Heyford.

Debora Cahn serves as showrunner on Season 3 and lead writer for the series' scripts. Alex Graves is expected to helm multiple episodes again. Cahn, Graves, and Russell also executive produce alongside Janice Williams and Peter Noah.

The Diplomat Season 3 will premiere on Netflix with all episodes on Thursday, October 16, 2025. Seasons 1 and 2 are currently available to stream on Netflix. Season 4 is already greenlit.