Mountainhead: Full list of cast and characters explored

The satirical comedy-drama television film, Mountainhead, premiered on HBO Max on May 31, 2025. Starring Steve Carell, Jason Schwartzman, Cory Michael Smith, and Ramy Youssef, the film follows four friends from wealthy backgrounds who come together for a retreat as the world is overwhelmed by disinformation generated and spread through AI on the social media platform Traam.

The movie is written and directed by Jesse Armstrong, who previously worked on shows such as Black Mirror (2011), Veep (2012), and Succession (2018-2023). Mountainhead is Armstrong's first full-length project as a director, whereas prior to this, he helmed two short films: No Kaddish in Carmarthen (2013) and Incident on the Northern Line (2015).

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The primary cast of Mountainhead

1) Steve Carell as Randall Garrett

Steve Carell is Randall Garrett (Image via Getty)

Steve Carell plays Randall Garrett in Mountainhead. In the film, he has recently received a diagnosis of cancer that is incurable. However, he is hopeful that Traam, which deals with modern science elements, including AI, will be able to come up with a cure for his condition.

Golden Globe award-winning actor Steve Carell is one of the most popular performers in the Hollywood film and television industry. Some of the projects he is best recognized for include Little Miss Sunshine (2006), Foxcatcher (2014), and The Office (2005–2011; 2013).

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2) Jason Schwartzman as Hugo "Souper" Van Yalk

Jason Schwartzman is Hugo Van Yalk (Image via Getty)

Jason Schwartzman portrays Hugo Van Yalk in the new film. Among the four friends central to the movie's plot, he is the least wealthy with a net worth of over $500 million, and he is very aware of the same. Meanwhile, "Mountainhead," the mountain home where the friends go for a retreat, belongs to Hugo.

Jason Schwartzman has several renowned acting credits to his name, including Rushmore (1998), Fantastic Mr. Fox (2009), and The Hunger Games: The Ballad of Songbirds & Snakes (2023).

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3) Cory Michael Smith as Venis "Ven" Parish

Cory Michael Smith is Venis Parish (Image via Getty)

Cory Michael Smith plays Venis Parish in Mountainhead. Venis is the owner of Traam, a social media platform that is guilty of producing and distributing large amounts of AI-facilitated misinformation.

Some of the projects Cory Michael Smith has been credited for include Gotham (2014-2019), First Man (2018), and Saturday Night (2024).

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4) Ramy Youssef as Jeffrey "Jeff" Abredazi

Ramy Youssef is Jeffrey Abredazi (Image via Getty)

Ramy Youssef depicts Jeffrey Abredazi in the film. He is the owner of Bilter, a company specializing in AI. Meanwhile, his friend Ven wishes to acquire his company, but Jeff doesn't want this to happen.

Golden Globe Award-winning actor Ramy Youssef has been associated with several projects as a writer, producer, and director. Some of his most renowned works include Ramy (2019- 2022), Poor Things (2023), and The Studio (2025).

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Additional cast of the film

The rest of the film's cast, according to IMDb, includes the following names:

• Daniel Oreskes as Dr. Phipps
• Hadley Robinson as Hester
• David Thompson as Leo
• Ali Kinkade as Berry Oliphant
• Ava Kostia as Paula
• Alex Peña as an Argentinian business leader
• Amie MacKenzie as Janine
• Larkin Bell as a nanny
• Capri Eaton as Baby Sabre
• Emmi Eaton as Baby Sabre

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Mountainhead is currently streaming on HBO Max. Furthermore, based on where the audience is trying to access it from, the film is also available on Amazon Prime Video, Hulu, Disney+, and Sky Atlantic.