| Colin Farrell | Detective Ray Velcoro |
| Rachel McAdams | Detective Ani Bezzerides |
| Taylor Kitsch | Officer Paul Woodrugh |
| Kelly Reilly | Jordan Semyon |
| Vince Vaughn | Frank Semyon |
| Ritchie Coster | Mayor Austin Chessani |
| David Morse | Eliot Bezzerides |
| Christopher James Baker | Blake Churchman |
| Chris Kerson | Nails |
| Ronnie Gene Blevins | Stan |
| Andy Mackenzie | Ivar |
| Timothy V. Murphy | Osip Agronov |
| Leven Rambin | Athena Bezzerides |
| W. Earl Brown | Detective Teague Dixon |
| Afemo Omilami | Police Chief Holloway |
| James Frain | Lieutenant Kevin Burris |
| Michael Irby | Detective Elvis Ilinca |
| Matt Battaglia | Commander Floyd Heschmeyer |
| Adria Arjona | Emily |
| Yara Martinez | Felicia |
| Lera Lynn | Singer |
| Molly Hagan | Mrs. Harris |
| Ashley Hinshaw | Lacey Lindel |
| Agnes Albright | Veronica Chessani
(as Agnes Olech) |
| Christian Campbell | Richard Brune |
| Trevor Larcom | Chad Velcoro |
| Courtney Halverson | Erica Jonson |
| Jon Lindstrom | Jacob McCandless |
| Chet Grissom | Bart Sallis |
| Alain Uy | Ernst Bodine |
| Carla Vila | Danielle Delvayo |
| Stevin Knight | Dan Howser |
| Riley Smith | Steve Mercer |
| Gia Mora | Mrs. Conroy |
| Cooper Roth | Aspen Conroy |
| Drew Waters | Paul Trevor |
| Wilke Itzin | Webcam Owner |
| Charles Maceo | California Highway Patrol Police #1 |
| Jamison Jones | Will Davidson |
| Anjul Nigam | Ventura County Medical Examiner |
| Sol Landerman | Michael Bulgari
(as Solomon Shiv) |
| Mustafa Speaks | California Highway Patrol Police #2
(as Coley Mustafa Speaks) |
| Ashli Haynes | Webcam Girl #1 |
| Rosalie McIntire | Webcam Girl #2 |
| Lidia Porto | Panticapaeum Maid #1 |
| Ivet Corvea | Panticapaeum Maid #2 |
| Avi Bernard | Male Deputy #1 |
| Brett Edwards | Male Deputy #2 |
| Marc Abbink | Upscale Man in Casino
(uncredited) |
| Vincent M. Biscione | Poker Player
(uncredited) |
| Oceane Bucaille | Student
(uncredited) |
| Ashley Chaney | Casino Guest
(uncredited) |
| Ben Guenther | School Parent
(uncredited) |
| Jacqui Holland | Webcam Girl
(uncredited) |
| Rich Young Lee | Vinci Investor
(uncredited) |
| Bo McCann | Ben Caspere
(uncredited) |
| Tina Redmond | Crossing Guard
(uncredited) |
| Emily Rhoads | Casino Guest
(uncredited) |
| Terra Kimberly Scott | Casino Gambler
(uncredited) |
| Bruce M. Stockert | Casino Guest
(uncredited) |
| Pamela Drake Wilson | Casino Dealer
(uncredited) |
| Raquel Yasmin | Webcam Girl
(uncredited) |