The Alienist (TV) Cast
The cast of The Alienist. Updated on September 14, 2025.
202 actors
Daniel Brühl
as Laszlo Kreizler (18 episodes)

Daniel Brühl portrays the character Laszlo Kreizler in The Alienist. Dr. Laszlo Kreizler is a brilliant and pioneering criminal psychologist, often referred to as an 'alienist,' which was the term given to early forensic psychologists. He is determined to unravel the mind of a serial killer by studying the psychological motives behind the gruesome murders.

Luke Evans
as John Moore (18 episodes)

Luke Evans plays the character of John Moore in The Alienist. John Moore is a newspaper illustrator and a close friend of Dr. Kreizler. He becomes fascinated with the investigation and joins forces with Kreizler to solve the horrific crimes.

Dakota Fanning
as Sara Howard (18 episodes)

Dakota Fanning portrays the character Sara Howard in The Alienist. Sara Howard is a headstrong and ambitious secretary in the New York City Police Department. Despite the limitations placed on women in the 19th century, she aspires to become the first female police detective and joins Dr. Kreizler and John Moore in their investigation.

Matthew Shear
as Lucius Isaacson (18 episodes)

Matthew Shear plays the character Lucius Isaacson in The Alienist. Lucius Isaacson works as a police department illustrator. He assists Dr. Kreizler and his team in the investigation by gathering visual evidence and creating sketches of crime scenes. He is also the brother of Marcus Isaacson.

Brian Geraghty
as Theodore Roosevelt (10 episodes)

Brian Geraghty portrays the character Theodore Roosevelt in The Alienist. Theodore Roosevelt is the police commissioner of New York City and is known for his progressive and reformist ideas. He supports Dr. Kreizler and his team in their unconventional methods, providing them with resources and access to restricted information.

Douglas Smith
as Marcus Isaacson (18 episodes)

Douglas Smith plays the character Marcus Isaacson in The Alienist. Marcus Isaacson works alongside his brother Lucius as a police department illustrator. He is skilled in using emerging forensic techniques, such as fingerprint analysis and bloodstain pattern analysis, to aid in the investigation.

Robert Wisdom
as Cyrus Montrose (18 episodes)

Robert Wisdom portrays the character Cyrus Montrose in The Alienist. Cyrus Montrose is a trusted ally of Dr. Kreizler. He serves as Kreizler's bodyguard and driver, and his past connections to the criminal underworld prove valuable in the investigation.

Rosy McEwen
as Libby Hatch (8 episodes)

Rosy McEwen plays the character Libby Hatch in The Alienist. Libby Hatch is an enigmatic and troubled woman who becomes entangled in the investigation. Her complex relationship with the killer holds vital clues that help Dr. Kreizler and his team understand the murderer's motives.

David Wilmot
as Captain Connor (10 episodes)
Melanie Field
as Bitsy Sussman (8 episodes)
Q'orianka Kilcher
as Mary Palmer (10 episodes)
Matt Lintz
as Stevie Taggert (10 episodes)
Sara Vickers
as Jane Gooding (1 episode)
Lewin Lloyd
as Beansie (2 episodes)
Jacob James Beswick
as Young Roundsman (1 episode)
Clare Calbraith
as Mrs. Zweig (1 episode)
Jack Kesy
as Henry Wolff (1 episode)
Emanuela Postacchini
as Flora (1 episode)
Joe Bone
as Police Clerk (1 episode)
John Connors
as Roundsman Gillooly (1 episode)
Maria Teresa Creasey
as Ezra's Mother (1 episode)
Isabelle De Hertogh
as Two-Ton Annie (1 episode)
Andy Gathergood
as Ezra's Father (1 episode)
Michael Jibson
as Dr. Fuller (1 episode)
Sean Young
as Mrs. Van Bergen (4 episodes)
Michael Ironside
as J. P. Morgan (4 episodes)
Falk Hentschel
as Biff Ellison (2 episodes)
Virág Bárány
as Mrs. Rajk (1 episode)
Dan Bradford
as Santorelli Priest (1 episode)
Richard Bremmer
as Mortician (1 episode)
Gabriele Caprio
as Young Tough #3 (1 episode)
Marcus D'Amico
as Charlie Delmonico (1 episode)
Ezra Fieremans
as Ernestine (1 episode)
Jacqueline Defferary
as Tessie (2 episodes)
Max Gabbay
as Italian Tough #2 (1 episode)
Gáspárfalvi Dorka
as Berthe Rajk (1 episode)
Giovanni D'Aleo
as Street Kid (1 episode)
Yusuf Hofri
as Paresis Hall Boy #10 (1 episode)
Kertész Péter
as Kreizler Institute Priest (1 episode)
Aldo Maland
as Paresis Hall Boy #2 (2 episodes)
Mary Stockley
as Mrs. Tinker (1 episode)
Gerald Tyler
as Charles H. Matchett (1 episode)
Scott Alexander Young
as Roundsman Hanrahan (1 episode)
Tracy Sallows
as Abigail Bell (1 episode)
Matthew Van Oss
as Milton (1 episode)
Samuel Brown
as Bath House Boy #4 (1 episode)
Gavin Drea
as Roundsman Barclay (1 episode)
Jamie Kaye
as Sally (3 episodes)
Mitchell Norman
as Bath House Boy #3 (1 episode)
Kristóf Ódor
as Van Bergen Servant (1 episode)
Kate Phillips
as Laura Boone (1 episode)
Kingston Taylor
as Bath House Boy #2 (1 episode)
Tate Pitchie-Cooper
as Fatima (3 episodes)
Rio Thake
as Bath House Boy #7 (1 episode)
Eugenia Caruso
as Mrs. Santorelli (3 episodes)
Kate Dickie
as Scotch Ann (1 episode)
Fernanda Dorogi
as Mother in Park (1 episode)
Amanda Hadingue
as Mrs. Gorenko (1 episode)
Katherine Kingsley
as Mrs. Williams (1 episode)
Ash Matthews
as Charles Blythe (1 episode)
Philip Rosch
as Dr. Cahill (1 episode)
Gábor Urmai
as Dentist Patient (1 episode)
Nicolas Bro
as Jacob Riis (3 episodes)
Peter McRobbie
as Mayor William L. Strong (3 episodes)
Freddie Stewart
as Nick Oldham (2 episodes)
Stephen Louis Grush
as Jesse Pomeroy (1 episode)
Bálint Adorjáni
as Delmonico's Waiter (2 episodes)
William Gaminara
as Alexander MacLeod (1 episode)
Laurel Lefkow
as Mrs. Isaacson (2 episodes)
Ania Marson
as Miss Effie (1 episode)
Lewis McGowan
as Boot Black (1 episode)
Colin Moody
as Officer Lasky (1 episode)
Anson Boon
as Paresis Hall Boy #5 (1 episode)
Geoffrey Thomas
as Roberts (3 episodes)
David Warner
as Professor Cavanaugh (1 episode)
Philip Broadbent
as Priest (1 episode)
Steven Pacey
as Mr. Van Bergen (2 episodes)
Francis McBurney
as O'Rourke Bartender (2 episodes)
Max Fincham
as Thomas (2 episodes)
Hans Peterson
as Well Dressed Man (1 episode)
Tommy Rodger
as Peter (3 episodes)
Jefferson White
as Lincoln Steffens (4 episodes)
Antonio Magro
as Paul Kelly (4 episodes)
Nicholas Asbury
as Dr. Tuthill (2 episodes)
Ed Birch
as Dr. Clark Wissler (1 episode)
Gados Béla
as Counter Clerk (3 episodes)
Oliver Cater
as Rosie (4 episodes)
George Lenz
as Franz Boas (1 episode)
Zsolt Páll
as Bathhouse Cop (2 episodes)
Sean McGinley
as Bishop Potter (3 episodes)
Jonathan Peck
as JP Morgan's Butler (1 episode)
Kincsö Pethö
as Angry Italian Woman (1 episode)
Tom Pilath
as Angry German Man (1 episode)
Vivien Rujder
as Young Woman at Blackwell's (1 episode)
Márk Szekulesz
as Mr. Rajk (2 episodes)
Levente Törköly
as Male Attendant at Blackwell's (1 episode)
Rocci Williams
as Jack McManus (1 episode)
Cassi Thomson
as Eliza (1 episode)
Peter Schueller
as Crank Operator (1 episode)
David Meunier
as Adam Dury (1 episode)
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