Mountainhead cast and character guide: Who plays whom in the HBO film?

Mountainhead is a television film written and directed by Jesse Armstrong who is mostly known as the creator of the TV series Succession. The film was released on HBO Max on May 31, 2025. It revolves around four rich people who meet for a short retreat amid major global turmoil. The official synopsis reads:

"A group of billionaire friends get together against the backdrop of a rolling international crisis."

The executive producers of the film include Armstrong, Jill Footlick, Will Tracy, Jon Brown, Frank Rich, Lucy Prebble, Tony Roche and Mark Mylod among others. Let us take a look at its major cast members.

Mountainhead cast and character guide

Mountainhead features several actors who are known for their comedic timing.

1) Steve Carell as Randall Garrett

Steve Carell plays the role of Randall Garrett, who is a billionaire from the tech industry. He is the oldest among the four group of friends. As Mountainhead begins, Randall is also the richest in the group. As the storyline moves, he struggles to maintain his status.

Carell has had a long career in television and films, and he has done projects like The Office, The 40 Year Old Virgin, and The Big Short, among others.

2) Cory Michael Smith As Venis Parish

Cory Michael Smith plays Venis, who runs an artificial intelligence company that is responsible for creating the turmoil that sets the film's backdrop. Cory has done films like Saturday Night, Wonderstruck, and Carol as well as the Broadway play Breakfast at Tiffany's.

3) Jason Schwartzman as Hugo Van Yalk

Jason Schwartzman portrays Hugo Van Yalk aka Souper, who owns the namesake lodge up in the mountains. Even though he is rich, Hugo is the poorest among the four of them, and the rest make fun of him because of it. This leads him to make decisions that Randall would like.

Jason has done films like The Darjeeling Limited, Saving Mr. Banks, and Scott Pilgrim vs. the World.

4) Ramy Youssef as Jeff

Ramy Youssef is Jeffrey Abredazi aka Jeff, in Mountainhead. Unlike the rest, he is more aware of the consequences of their business practices. This creates some rift among the four, which takes the plot forward.

Ramy is mostly known for starring in the Hulu series Ramy and movies like Poor Things, Why Him? and Wish.

5) Other members and supporting cast of Mountainhead

Hadley Robinson as Hester
Ali Kinkade as Berry
Andy Daly as Casper
Ava Kostia as Paula
Daniel Oreskes as Dr. Phipps
David W. Thompson as Leo
Amie MacKenzie as Janine

More about Mountainhead

Mountainhead is the directorial debut of Jesse Armstrong, who also wrote it. The film is edited by Bill Henry and Mark Davies. Marcel Zyskind is the director of photography.

Armstrong spoke to Variety about making the film after Succession. He said:

“It’s a little bit scary after a ‘Succession’ type of thing that’s well-regarded. I knew it was going to be a big thing for me to do the next thing. Maybe it’d be a good idea to run at it fast rather than stewing on it for five years on my second album.”