Emile Hirsch

Character: Christopher McCandless / Alexander Supertramp

Marcia Gay Harden

Character: Billie McCandless

William Hurt

Character: Walt McCandless

Jena Malone

Character: Carine McCandless / Additional Narration (voice)

Brian H. Dierker

Character: Rainey

Catherine Keener

Character: Jan Burres

Vince Vaughn

Character: Wayne Westerberg

Kristen Stewart

Character: Tracy Tatro

Hal Holbrook

Character: Ronald "Ron" Franz

Thure Lindhardt

Character: Mads

Signe Egholm Olsen

Character: Sonja

Jim Gallien

Character: Jim Gallien

James J. O'Neill

Character: Graduation Reader

Malinda McCollum

Character: Waitress

Paul Knauls

Character: Building Manager

Zach Galifianakis

Character: Kevin

Craig Mutsch

Character: Wayne's Crew #1

Jim Beidler

Character: Wayne's Crew #2

John Decker

Character: Hutterite #1

John Hofer

Character: Hutterite #2

Jerry Hofer

Character: Hutterite #3

Terry Waldner

Character: Hutterite #4

Robin Mathews

Character: Gail Borah

Candice Campos

Character: Bar Girl

Steven Wiig

Character: Lee's Ferry Ranger

Floyd Wall

Character: Man In Phone Booth

Bryce Walters

Character: Christopher McCandless (age 4)

Jim Davis

Character: Immigration Officer

Cheryl Francis Harrington

Character: Social Worker

R. D. Call

Character: Bull

Haley Ramm

Character: Carine McCandless (age 11)

Merritt Wever

Character: Lori

Everett 'Insane Wayne' Smith

Character: Insane Cain

John Jabaley

Character: Announcer

Leonard Knight

Character: Leonard Knight

Matt Contreras

Character: Book Shopper #1

Denise Sitton

Character: Book Shopper #2

Sharon Olds

Character: Additional Narration (voice)

Carine McCandless

Character: Additional Narration (voice)

J. Nathan Simmons

Character: Tourist (uncredited)

Parris Mosteller

Character: Young Boy (voice) (uncredited)

Timothy Levine

Character: Atlanta Braves fan (uncredited)

Haley Sweet

Character: Bank Teller (uncredited)

Aaron Wayne Hill

Character: Big Wheel Boy (uncredited)

Bart the Bear 2

Character: Bear