Steve Martin
as Gil Buckman

Mary Steenburgen
as Karen Buckman

Dianne Wiest
as Helen Buckman Lampkin Bowman

Jason Robards
as Frank Buckman

Rick Moranis
as Nathan Huffner

Tom Hulce
as Larry Buckman

Martha Plimpton
as Julie Buckman-Lampkin Higgins

Keanu Reeves
as Tod Higgins

Harley Jane Kozak
as Susan Buckman

Joaquin Phoenix
as Garry Buckman-Lampkin

Dennis Dugan
as David Brodsky

Eileen Ryan
as Marilyn Buckman

Helen Shaw
as Grandma

Jasen Fisher
as Kevin Buckman

Paul Linke
as George Bowman

Alisan Porter
as Taylor Buckman

Zachary La Voy
as Justin Buckman

Ivyann Schwan
as Patty Huffner

Alex Burrall
as Cool Buckman

Lowell Ganz
as Stan

Rance Howard
as Dean at College

Max Elliott Slade
as Young Gil Buckman

Clint Howard
as Lou

Lamont Lofton
as Fotomat Clerk

Erika Rafuls
as Amy

Jordan Kessler
as Matt

Billy Cohen
as Eddie

Isabel Cooley
as Barbara Rice

Walter von Huene
as Opposing Coach

Howie Dorough
as Kid in Classroom (uncredited)

Greg Gerard
as Doctor Lucas

Paul Keeley
as Kevin Buckman - Age 21

Claudio Jacobellis
as Student 1 at College

W. Bruce O'Donoghue
as Umpire

Hillary Matthews
as Student 2 at Collage

Sherry Ferguson
as Screaming Co-ed

Todd Hallowell
as Track Official

Richard Kuhlman
as Young Frank Buckman

Charmin Lee
as Nurse at Hospital