Keith Gordon as Arnie Cunningham

John Stockwell as Dennis Guilder

Alexandra Paul as Leigh Cabot

Robert Prosky as Will Darnell

Harry Dean Stanton as Rudolph Junkins

Christine Belford as Regina Cunningham

Roberts Blossom as George LeBay

William Ostrander as Buddy Repperton

David Spielberg as Mr. Casey

Malcolm Danare as Moochie Welch

Steven Tash as Richard Trelawney

Stuart Charno as Don Vandenberg

Kelly Preston as Roseanne

Marc Poppel as Chuck

Robert Darnell as Michael Cunningham

Douglas Warhit as Bemis

Richard Collier as Pepper Boyd

Bruce French as Mr. Smith

Keri Montgomery as Ellie

Jan Burrell as Librarian

Charles Steak as Shoppie

Art Evans as Auto Assembly Worker (uncredited)

John Richard Petersen as High School Student (uncredited)