Who is Callum Ellis in The Diplomat Season 3 — And Who Plays Him?

Season 3 of Netflix’s The Diplomat introduces a compelling new character, Callum Ellis, who significantly impacts Kate Wyler’s life, both professionally and personally. His arrival deepens the political drama and adds emotional complexity to Kate’s already turbulent journey.

Who Is Callum Ellis in The Diplomat?

Callum Ellis appears midway through Season 3, during Grace Penn’s presidency—after the sudden death of President Rayburn and Hal Wyler becoming Vice President. Kate and Hal’s marriage is fractured, and they are now separated, living on different continents.

In this emotionally vulnerable period, Kate meets Callum, a calm and observant figure who immediately forms a strong connection with her. Their bond soon evolves into a secret romantic relationship.

Callum Ellis: More Than Just a Love Interest

Although he seems like a quiet, mysterious man, Callum is actually a covert MI6 intelligence officer, referred to as a “bird watcher.” He becomes involved in a major geopolitical crisis after discovering a Russian nuclear submarine off the UK coast—potentially connected to a secret weapon known as Poseidon.

Callum chooses not to inform his own government, claiming he cannot trust anyone within the system. Instead, he turns to Kate, seeking U.S. support for a high-stakes operation.

How Callum Complicates Kate’s World

• He challenges Kate emotionally at a moment when she is heartbroken over Hal.

• He brings her into a dangerous international secret involving Russia.

• He forces her to question trust, loyalty, and political alliances.

Hal notices the chemistry between Kate and Callum and warns her that if he can see it, others can too—putting Kate at personal and political risk.

Who Plays Callum Ellis?

Aidan Turner, the acclaimed Irish actor, brings charm and depth to Callum Ellis.

Aidan Turner at a Glance

• Nationality: Irish (Born in Dublin)

• Background: Skilled ballroom and Latin dancer in his youth

• Acting Training: Gaiety School of Acting (Graduated 2004)

Notable Roles

• Kíli – The Hobbit Trilogy

• Ross Poldark – Poldark

• Leonardo da Vinci – Leonardo

• Philip Lombard – And Then There Were None

• Dr. Joe O’Loughlin – The Suspect

Turner has also performed on stage in productions like Romeo and Juliet, Cyrano, and Lemons x5, and has even been considered for the role of James Bond.

Why Callum Matters in The Diplomat

Callum Ellis is not just a love interest—he’s a moral test for Kate. His secrets, loyalty, and vulnerabilities make him one of the most layered characters introduced in Season 3, further raising the question: In politics, who can truly be trusted?