Hugh Jackman
Charlie Kenton

Dakota Goyo
Max Kenton

Evangeline Lilly
Bailey Tallet

Kevin Durand
Ricky

Anthony Mackie
Finn

Hope Davis
Aunt Debra

James Rebhorn
Marvin

Karl Yune
Tak Mashido

Sophie Levy
Big Sister

Tess Levy
Little Sister

Olga Fonda
Farra Lemkova

John Gatins
Kingpin

Gregory Sims
Bill Panner

Torey Adkins
Large Texan Man

Phil LaMarr
ESPN Boxing Commentator

John Hawkinson
San Leandro Gentleman #2

David Alan Basche
ESPN Boxing Commentator

Julian Gant
Starblaze Arena Reporter

Peter Carey
Bing Arena Announcer

Dan Lemieux
Bing Arena Ref

Ricky Wayne
Underground Promoter

Taris Tyler
Robot Promoter

Kevin Dorman
Atom Performance Capture

John Manfredi
Sergei Lemkova

Mike Ancrile
Fight Fan (uncredited)

Leah Barkoff
Upscale Fight Fan (uncredited)

Ben Hernandez Bray
Ricky's Henchman (uncredited)

Ron Causey
Kingpin's Henchman (uncredited)

Johnny Flynn
ESPN Commentator (uncredited)

Logan Fry
Rabid Fight Fan (uncredited)

Kef Lee
Zeus Robot Handler #1 (uncredited)

Megan Mockensturm
Fight Fan (uncredited)

Anton Narinskiy
Farra's Body Guard (uncredited)

Chris Newman
Starblaze Security Guard (uncredited)

Alan D. Purwin
Helicopter Pilot (uncredited)

Miguel Sandoval
Judge (uncredited)

Jojuan Westmoreland
Zoo Fight Fan (uncredited)

Amanda Bright
Ricky's Girl (uncredited)

Rima Fakih
Self (uncredited)