Ross Lynch as Jeffrey Dahmer

Alex Wolff as John 'Derf' Backderf

Anne Heche as Joyce Dahmer

Dallas Roberts as Lionel Dahmer

Liam Koeth as Dave Dahmer

Nancy Telzerow as Carol Backderf

Tommy Nelson as Neil

Harrison Holzer as Mike

Brigid Naughton as Melody

Cameron McKendry as Moose

Katie Stottlemire as Penny

Brady M.K. Dunn as Bossy

Jake Ingrassia as Gooch

Michael Ryan Boehm as Shorty

Ben Zgorecki as Bully Jock

Dontez James as Charlie Smith

Miles Robbins as Lloyd Figg

Gabriela Novogratz as Lisa Watkins

Jack DeVillers as Oliver Zlatka

Dave Sorboro as Steven Hicks

Joey Prines as Snarky Slacker

Kris Smith as Ms Bowles

Adam Kroloff as Mr Burlman

Christopher Mele as Mr Fedele

Joey Vee as Mr Hicks

Tom Lepera as Mr Lapolla

Vincent Kartheiser as Dr Matthews

Maryanne Nagel as Mrs Woodard

Sydney Meyer as Bridget

Lauren Rhodes as Aide

Tom Luce as Vice President Walter Mondale

Carmen Gangale as Grocery Store Manager

Shane Patrick O'Neill as Restaurant Manager

Joe Fishel as Market Shopper

Andrew Gorell as English Teacher

Susan Bennett as Musical Director

Nicholas Hulstine as Prom Photographer

Zachary Davis Brown as Freshman Boy

Lily Kozub as Freshman Girl

Clayton Frank as Bus Student 1 (uncredited)