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 Himself
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 Himself
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)
