Charlie Hunnam as Stanley Kaminski

Jack O'Connell as Walter 'Lion' Kaminski

Jessica Barden as Sky

Fran Kranz as Buck

Jonathan Majors as Pepper

John Cullum as Yates

Owen Burke as Meadows

Meredith Holzman as Darlene

Nick Mullen as Clay Carlson

Jere Shea as Stepfather McGinty

Patrick M. Walsh as Lefty Denunzio

Lucien Spelman as Roman

Naheem Garcia as Clem

Katie Duncan as Front Desk Clerk

Johnno Wilson as Reggie

Robert Otis as Cue Ball

Margaret Devine as Mother McGinty

Frank Ridley as Burly Father

Wendy Overly as Waitress

Michael Tow as Kind Father

Moira Driscoll as Bus Driver

Bill Thorpe as Zeus

Scott Fielding as Milos

Ed LaVache as Referee

James Peralla as Domo

Thomas J Berry as Train Patron (uncredited)

Christopher Cagle as Pepper's Crew (uncredited)

Christina Calvao as Amtrak Employee (uncredited)

Ken Cheeseman as Old Senior (uncredited)

Ellen Collins as Diner Waitress (uncredited)

Jamie Ghazarian as College Girl (uncredited)

Jed Griswold as Boxing Patron (uncredited)

Tony Ionno as Bar Patron (uncredited)

Manny Jagroop as Pepper's Head Thug (uncredited)

Dawayne Jordan as San Francisco Chinatown Cop (uncredited)

Joseph Oliveira as Joey (uncredited)

Mel Powell as San Francisco Police Detective (uncredited)

Juliana Redden as Bar Patron (uncredited)

Billy Silvia as San Francisco Detective (uncredited)

David Torres Jr. as Lefty's Buddy (uncredited)

Bobby Garrafa as College Kid (uncredited)