If you’ve spent any time tracking the awards race lately, you know that Edward Berger’s religious thriller is the kind of movie that gets people talking. It isn't just about the red robes or the smoke. Honestly, it’s about the faces. When people ask who starred in Conclave, they’re usually looking for Ralph Fiennes, but the bench of talent here is remarkably deep.
This isn't your typical slow-burn church drama. It’s a political nail-biter. Think Succession but with more incense and significantly higher stakes for the soul of the world.
Ralph Fiennes and the Weight of the Papacy
At the center of it all is Ralph Fiennes. He plays Cardinal Thomas Lawrence. He’s the guy tasked with running the Conclave—the secret election that happens after a Pope dies. Fiennes is incredible here because he isn't playing a hero. He’s playing a man who is exhausted. He’s having a crisis of faith right when he needs it most.
You’ve seen him as Voldemort or M. in Bond, but this is different. It’s quiet. It’s all in the eyes.
Lawrence is the Dean of the College of Cardinals. That means he has to wrangle a group of ego-driven men who all secretly (or not so secretly) want the top job. Fiennes captures that specific type of middle-management hell where you're trying to follow the rules while everyone else is trying to rewrite them. It’s a performance of restraint.
The Heavy Hitters: Stanley Tucci and John Lithgow
Then you have the contenders.
Stanley Tucci plays Cardinal Bellini. He’s the progressive. He’s the guy who thinks the Church needs to join the 21st century or risk becoming a museum. Tucci brings this intellectual sharpness to the role. He doesn’t want the job, or so he says, which of course makes him the perfect candidate in the eyes of many.
Compare that to John Lithgow.
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Lithgow plays Cardinal Tremblay. If Bellini is the heart, Tremblay is the ambition. He’s the kind of guy who has been measuring the curtains in the papal apartments for years. Lithgow is a master at playing "distinguished with a hint of menace." You never quite know if he’s being sincere or if he’s just the smartest politician in the room. Watching him and Tucci trade barbs in a candlelit hallway is basically why we go to the movies.
The Wild Cards: Lucian Msamati and Sergio Castellitto
The movie does a great job of showing that the Vatican isn't just a European club anymore.
Lucian Msamati plays Cardinal Adeyemi. He’s a powerhouse. He represents the growing influence of the Church in Africa. He’s conservative, charismatic, and carries a massive amount of weight in the voting process. Msamati is a veteran of the stage and Game of Thrones, and he brings a massive, booming presence that makes the other Cardinals look a bit small by comparison.
On the other side of the ideological aisle, you have Sergio Castellitto as Cardinal Tedesco.
He’s the traditionalist. He wants to go back to Latin masses and hardline stances. He’s fiery. He’s loud. He’s the guy who thinks the world is falling apart because the Church got soft. Castellitto plays him with this incredible, restless energy. He’s always smoking a vape or pacing around, looking like he’s ready to start a crusade in the middle of the Sistine Chapel.
Isabella Rossellini: The Silent Power
Usually, women don't get much to do in movies about the Vatican. It’s a boys' club by design. But Isabella Rossellini as Sister Agnes is a stroke of genius.
She doesn't have a lot of dialogue. She doesn't need it.
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As the head of the nuns who handle the logistics—the cooking, the cleaning, the mundane details—she sees everything. She’s the fly on the wall. When she finally does speak, it’s like a thunderclap. Rossellini has this regal, terrifying stillness. She reminds the Cardinals (and the audience) that while the men are arguing about theology, the women are actually keeping the world turning.
Carlos Diehz and the Mystery of Benitez
The biggest surprise for most people checking out the cast list is Carlos Diehz.
He plays Cardinal Benitez. He’s a character the movie keeps under wraps for a long time. Benitez is the "Cardinal in pectore," meaning he was appointed in secret by the late Pope because he was working in a dangerous area (Kabul, in this case).
Diehz is a relatively new face to international audiences. That’s intentional. He needs to feel like an outsider. He has this calm, serene vibe that contrasts perfectly with the frantic, sweaty panic of the more established Cardinals. He’s the moral compass of the film, and his performance is what makes the ending—which is wild, by the way—actually work.
Why the Casting Works So Well
Berger didn't just hire "famous people." He hired actors who look like they’ve lived in these robes for decades.
The production design is so sterile and cold that you need actors with a lot of internal "heat" to balance it out. When you look at the wide shots of the Sistine Chapel, it looks like a painting. But when the camera zooms in on Fiennes or Lithgow, you see the pores, the sweat, and the doubt.
It’s also worth noting the source material. Robert Harris wrote the novel, and he’s a master of the "procedural thriller." The cast had to treat the voting process like a legal drama. It’s all about ballots, wax seals, and very specific rules. If the actors didn't take it seriously, it would feel silly. Because they play it with such gravity, it feels like the fate of the universe is at stake.
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Realism and the Vatican Aesthetic
A lot of work went into making these actors look the part.
The costumes were designed by Binny Daigeler. She didn't just make "costumes"; she made ecclesiastical vestments. The weight of the wool, the specific shade of "cardinal red"—it all affects how the actors move. You’ll notice Ralph Fiennes walks differently in this movie than he does in anything else. He’s weighted down.
The film was shot at Cinecittà Studios in Rome, and the sets are near-perfect recreations of the Vatican’s most private spaces. This environment forced the cast to stay in a specific headspace. You can't really "ham it up" when you're standing in a replica of the Sistine Chapel. The actors had to find the drama in the whispers.
What to Watch Next
If you’ve seen the film and are obsessed with the cast, there are a few places to go next to see them in a totally different light:
- Ralph Fiennes in The Menu: If you want to see him play a different kind of authority figure who is losing his mind, this is the one.
- Stanley Tucci in Big Night: Remind yourself how charming he can be when he isn't worrying about the future of the Catholic Church.
- Isabella Rossellini in Blue Velvet: For a total 180-degree turn from Sister Agnes.
- Edward Berger’s All Quiet on the Western Front: To see how the director handles tension and large-scale drama.
The brilliance of the Conclave cast is that they make a movie about men in rooms voting for a guy in a hat feel like the most intense thing you’ll see all year.
Next Steps for Enthusiasts
If you want to dive deeper into the world of the film, your best move is to pick up the original novel by Robert Harris. It provides a lot of the internal monologue for Cardinal Lawrence that Fiennes has to convey with just his face. Also, keep an eye out for the "Making Of" featurettes often released during awards season; the technical detail regarding the costumes and the set construction at Cinecittà is genuinely fascinating for anyone interested in how high-level cinema is constructed. For those curious about the actual process, the Vatican's own "Universi Dominici Gregis" is the actual apostolic constitution that governs the rules shown in the film. Reading the real rules makes the "cheating" and maneuvering by the characters in the movie feel even more scandalous.