‘The Diplomat’ Season 3 Trailer: See Allison Janney & Bradley Whitford Back Together (VIDEO)

Kelli Boyle September 18, 2025, 10:45 am

Tensions couldn’t be higher in The Diplomat Season 3 trailer. Netflix released the official trailer on Thursday, September 18, along with new photos from the season. In the trailer above, a constant face-off is presented between Season 3’s central couples: Kate (Keri Russell) and Hal (Rufus Sewell), and Grace (Allison Janney) and Todd (Bradley Whitford). The latter pair has been upped to president and first gentleman following the shocking death of President William Rayburn (Michael McKean) in last season’s finale. As Kate warns, only she and Hal know just how “terribly flawed” the new president is.

The previous teaser for The Diplomat Season 3 was packed with clips of The West Wing reunion between Janney and Whitford, teasing the immediate aftermath of Rayburn’s death. The new trailer goes even deeper, showing the early days of the Penn administration. Grace’s past is coming back to haunt her as her involvement in the strike against the British warship in Season 2 threatens to come out.

The British government is also playing defense, with Prime Minister Nicol Trowbridge (Rory Kinnear) as charged as ever. There’s also the first look at Aidan Turner‘s new character, who has a steamy moment with Kate in the trailer, and Kate’s ongoing flirtation with British Foreign Secretary Austin Dennison (David Gyasi) continues. Hal was speaking to the president when he died. How will that impact their relationship and their careers in Season 3?

Here’s everything we know about The Diplomat Season 3 and its West Wing reunion with Janney and Whitford.

When does The Diplomat Season 3 premiere?

Keri Russell as Kate Wyler, Rufus Sewell as Hal Wyler, Allison Janney as Grace Penn, Rory Kinnear as Nicol Trowbridge, David Gyasi as Austin Dennison in 'The Diplomat' Season 3 Episode 8

Clifton Prescod / Netflix

The Diplomat Season 3 premieres on Thursday, October 16, on Netflix. The streamer announced the premiere date on Monday, August 18, along with a teaser debut.

The Diplomat was renewed in early October 2024 before its Season 2 premiere on Halloween. Season 3 started production in New York and London in 2024.

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What is The Diplomat about?

The Diplomat stars Russell and Sewell as Ambassador Kate Wyler and Hal Wyler. Kate, the U.S. ambassador in London, and Hal, a former ambassador himself, are in a complicated marriage directly affected by how they operate at work. But the work and its dangers are the show’s main appeal.

In Season 2, struggling to rebuild the lives that were broken and the team that split apart, Kate’s worst fears unfold: The attack that brought her to the U.K. didn’t come from a rival nation; it came from inside the British government. As Kate chases the truth, her only real ally is her almost-ex-husband Hal, very much alive, and very much involved. She faces a fraught marriage, a complex dynamic with Dennison, and a threatening visit from Vice President Grace Penn.

Kate learned she was being primed to replace VP Penn at the end of Season 1, and she ended up crossing paths with the VP in Season 2. There was an admiration amid the subliminal rivalry between them. Russell’s character has serious apprehensions about taking on the role, which would require her to be more glamorous and performative than she finds valuable. But Penn makes clear that a clean, stylized aesthetic is an unavoidable prerequisite to being taken seriously as a woman in global politics.

Bradley Whitford as Todd Penn in 'The Diplomat' Season 3 Episode 6

Clifton Prescod / Netflix

Kate wasn’t privy to the secrets of Penn’s top-secret work, leading to a distrust in the VP that she called out in the back half of Season 2. As Kate confronted Penn in the high-intensity finale, Hal acted on his own and called President Rayburn. The president died on the call, and the season ended with Penn’s Secret Service rushing out onto the field where she and Kate were sparring.

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In Season 3, Kate lives the particular nightmare that is 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 (Gyasi), and an unnerving bond with First Gentleman Todd Penn.

Who is in The Diplomat Season 3 cast?

In addition to Russell, Sewel, Gyasi, and Janney, The Diplomat stars Ali Ahn as CIA Station Chief Eidra Park, Ato Essandoh as Stuart Hayford, Kate’s Chief of Staff, and Rory Kinnear as British Prime Minister Nicol Trowbridge. Recurring cast includes Celia Imrie, Nana Mensah, and Miguel Sandoval.

Deadline first reported that Whitford would join the Season 3 cast as Janney’s first gentleman. Series creator Debora Cahn was a writer on The West Wing, which is no doubt what made this reunion possible.

The Diplomat, Season 3 Premiere, Thursday, October 16, Netflix