Inception

Dom Cobb, a professional thief who specializes in conning secrets from his victims by infiltrating their dreams. DiCaprio was the first actor to be cast in the film. Brad Pitt and Will Smith were the first two choices and were offered the role, according to The Hollywood Reporter. Smith turned it down because he didn't understand it. Cobb's role is compared to "the haunted widower in a Gothic romance".

Arthur, Cobb's partner who manages and researches the missions. Gordon-Levitt compared Arthur to the producer of Cobb's art, "the one saying, 'Okay, you have your vision; now I'm going to figure out how to make all the nuts and bolts work so you can do your thing'". The actor did all but one of his stunt scenes and said the preparation "was a challenge and it would have to be for it to look real". James Franco was in talks with Christopher Nolan to play Arthur, but was ultimately unavailable due to scheduling conflicts.

Joseph Gordon-Levitt

Ariadne, a graduate student of architecture who is recruited to construct the various dreamscapes, which are described as mazes. The name Ariadne alludes to a princess of Greek myth, daughter of King Minos, who aided the hero Theseus by giving him a sword and a ball of string to help him navigate the labyrinth which was the prison of the Minotaur. Nolan said that Page was chosen for being a "perfect combination of freshness and savvy and maturity" not common in people that age. Page said their character acts as a proxy to the audience, as "she's just learning about these ideas and, in essence, assists the audience in learning about dream sharing". The role was written with Evan Rachel Wood in mind, but she turned it down. Emily Blunt, Rachel McAdams, Taylor Swift, Emma Roberts, Jessy Schram, and Carey Mulligan were also considered before it went to Page.

Saito, a Japanese businessman who employs Cobb for the team's mission. Nolan wrote the role with Watanabe in mind, as he wanted to work with him again after Batman Begins. Inception is Watanabe's first work in a contemporary setting where his primary language is English. Watanabe tried to emphasize a different characteristic of Saito in every dream level: "First chapter in my castle, I pick up some hidden feelings of the cycle. It's magical, powerful and then the first dream. And back to the second chapter, in the old hotel, I pick up [being] sharp and more calm and smart and it's a little bit [of a] different process to make up the character of any movie".

Ken Watanabe

Mal, Cobb's deceased wife. She is a manifestation of Cobb's guilt about the real cause of Mal's suicide. He is unable to control these projections of her, challenging his abilities as an extractor. Nolan described Mal as "the essence of the femme fatale," and DiCaprio praised Cotillard's performance, saying that "she can be strong and vulnerable and hopeful and heartbreaking all in the same moment, which was perfect for all the contradictions of her character". Kate Winslet was offered the role but turned it down as she couldn't see herself in the role.

Marion Cotillard

Eames, a sharp-tongued associate of Cobb. He is referred to as a fence but his specialty is forgery, more accurately identity theft. Eames uses his ability to impersonate others inside the dream world in order to manipulate Fischer. Hardy described his character as "an old, Graham Greene-type diplomat; sort of faded, shabby, grandeur—the old Shakespeare lovey mixed with somebody from Her Majesty's Special Forces", who wears "campy, old money" costumes.

Tom Hardy

Robert Fischer, the heir to a business empire and the team's target. Murphy said Fischer was portrayed as "a petulant child who's in need of a lot of attention from his father, he has everything he could ever want materially, but he's deeply lacking emotionally". The actor also researched the sons of Rupert Murdoch, "to add to that the idea of living in the shadow of someone so immensely powerful".

Cillian Murphy

Peter Browning, Robert Fischer's godfather and fellow executive at the Fischers' company. Berenger said Browning acts as a "surrogate father" to Fischer, who calls the character "Uncle Peter", and emphasized that "Browning has been with [Robert] his whole life and has probably spent more quality time with him than his own father".

Tom Berenger

Stephen Miles, Cobb's mentor and father-in-law, and Ariadne's college professor who recommends her to the team.

Michael Caine

Yusuf. Rao describes Yusuf as "an avant-garde pharmacologist, who is a resource for people, like Cobb, who want to do this work unsupervised, unregistered and unapproved of by anyone". Co-producer Jordan Goldberg said the role of the chemist was "particularly tough because you don't want him to seem like some kind of drug dealer", and that Rao was cast for being "funny, interesting and obviously smart".

Dileep Rao

Nash, an architect in Cobb's employment who betrays the team and is later replaced by Ariadne.

Lukas Haas