Played By: Anthony Perkins (the whole film series), Henry Thomas (Young Norman in Psycho IV)
- Adorkable: An awkward, shy momma's boy...at first.
- Affably Evil: When running a motel, one needs to be a people person.
- Anti-Villain: As he notes during his conversation with Marion Crane on private traps, "I was born into mine. I don't mind it anymore".
- Bad Liar: Although surprisingly enough, his stuttering and incessant chewing goes some way in convincing Arbogast that he had nothing to do with Marion's disappearance.
- A Date with Rosie Palms: Subtly implied in the original, and flat out shown in the remake.
- Dark and Troubled Past: Father died when he was five years old, leaving him in the care of an overbearing and somewhat incestuously inclined mother, who would emotionally abuse and degrade him.
- Doom Magnet: All of his love interests die as a result of getting too close to him.
- Driven to Madness: By his domineering mother, no less.
- Driven to Villainy: When his mother takes a lover and continues in bullying him.
- Extreme Doormat: To his mother, who deliberately made him dependent upon her after his father's death.
- Freudian Excuse: The abuse he was subject to by his mother when he was young.
- Gollum Made Me Do It: The last scene of the film is his mother personality plotting and scheming to blame Norman for the murders.
- Hidden Depths: Shown to be somewhat of a nihilistic philosopher during his brief interactions with Marion Crane.
- Kubrick Stare: Perhaps the most grim and soul destroying one in cinematic history.
- Momma's Boy: "A boy's best friend is his mother."
- Mommy Issues: One of the most famous cinematic examples.
- Monster Sob Story: And one that works on both the audience and the characters he encounters during the course of the series.
- Nice Guy: When Mommy doesn't take over...
- Oedipus Complex: Norman's mother deliberately isolated her five-year-old son from the outside world and made him utterly dependent on her after Mr Bates' death. Naturally enough, the twelve-year-old, completely co-dependent Norman then reacted rather badly to her remarriage.
- The Peeping Tom: In the parlor and hidden behind a painting, is a hole that looks into Cabin 1. He uses it to look at Marion Crane and Maureen Coyle.
- Reluctant Psycho: In Psycho II, Psycho III and Psycho IV.
- Serial Killer: In Psycho II, he is revealed to have killed 7 people before being captured at the end of the first film.
- Sex Is Evil and I Am Horny: When Norman finds himself attracted to women (such as Marion Crane), the "mother" side of his personality lashes out and seeks to rid him of his sinful urges by way of murder.
- Split Personality: Norman and his internalized mother.
- Split Personality Takeover: At the end of the first film. In the words of the psychiatrist: "Norman Bates no longer exists". He gets better in the sequel, however.
- Sweet Tooth: Is always seen with a bag of candy.
Played By: Janet Leigh (in Psycho)
- Decoy Protagonist: The Trope Codifier. While Sam and Norman both get a decent amount of screen-time in the early stages, the film is almost entirely her story. Then the shower scene happens...
- Redemption Equals Death: She would likely have ended up dead either way, but after having dinner with Norman she decides to return the stolen money to her employers and face the music.
Lila Loomis, née Crane
Played By: Vera Miles (in Psycho and Psycho II)
- Cruel and Unusual Death: Impaled through the mouth with a kitchen knife in Psycho II.
- Gone Horribly Right: Her plan to drive Norman insane again in the second film goes off very well. Unfortunately, she wasn't counting on Mary becoming sympathetic towards Norman, and definitely didn't foresee Emma Spool messing everything up.
- Hero Antagonist: Towards Norman, in Psycho and Psycho II, however, it's subverted in Psycho II, as the Antagonist side of this trope outweigh the Hero part despite Lila still fulfilling the same trope.
- Inspector Javert: A non-cop version. Still hounds Norman and views him as the irredeemable murderer after he's been released from the mental institution in Psycho II.
- Not So Different:
- Seeing as how Lila treats her daughter in Psycho II, she has more than a few similarities to the mother that drove Norman Bates insane.
- And, of course, there's the fact that she sets everything up to make Norman go insane again. Sure, she has a reason for not liking him because he killed her sister and several other people, but to attempt to send him back to the asylum and possibly kill again is just wrong.
- Vigilante Woman: In Psycho II, when she decides to take the law to her own hands to apprehend Norman herself after feeling the courts "protect criminals, not their victims," when Norman was released and declared sane.
Norma Bates, née Spool
Click here to see her corpse
Played By: Olivia Hussey (in Psycho IV)
- The Unseen: She's never seen until the end of Psycho. But she is often heard either by Norman or anyone not near the two in the first movie.
Mary Samuels (real name Loomis)
Played By: Meg Tilly (in Psycho II)
- Dead Person Impersonation: Impersonates Norman's mother with a robe, a wig and the kitchen knife in hope of stopping him from going insane again. It doesn't end well for her.
- Heel-Face Turn: She grows genuinely convinced of Norman's newfound sanity and at some point doesn't want to help her mother make him insane anymore.
- Kill the Cutie: She is shot dead by the police after an unlucky and tragic chain of reactions.
Played by: Diana Scarwid (in Psycho III)
Played by: Claudia Bryar (in Psycho II)
- Knife Nut: She is the knife-wielding murderer in Psycho II.
- Mummies at the Dinner Table: "Replaces" Norman's mother at the end of Psycho II and in Psycho III. Norman stuffs her body at the beginning of Psycho III.
- Parental Substitute: Sort of. In the most horrible way imaginable actually. She "replaces" Norman's mother as a mummy Norman talks to.
- The Reveal: She is Norma's sister.