Robin Williams as Lance Clayton

Alexie Gilmore as Claire Reed

Daryl Sabara as Kyle Clayton

Evan Martin as Andrew Troutman

Geoff Pierson as Principal Wyatt Anderson

Henry Simmons as Mike Lane

Mitzi McCall as Bonnie McBon

Jermaine Williams as Jason

Lorraine Nicholson as Heather Johnson

Morgan Murphy as Morgan

Toby Huss as Bert Green

Tom Kenny as Jerry Klein

Jill Talley as Make-Up Woman

Bruce Hornsby as Himself

Krist Novoselic as Newspaper Vendor

Bobcat Goldthwait as Limo Driver (uncredited)

Tony V. as Dr. Pentola

Naomi Glick as Ginger

Dan Spencer as Dan Spencer

Zachary Vitale as Peter (as Zach Sanchez)

Ellyn Jameson as Jennifer

Michael Thomas Moore as Chris

Ray Buckley as Metal Kid

Rebecca Erwin Spencer as Nosy Neighbor

Cheri Minns as Nosy Neighbor

Zazu as Nosy Neighbor

Mable Mae as Mabel

Deborah Horne as Dr. Dana

Riley Dean Stone as Bruce Hornsby's Mic Stand

Ray Buckley as Metal Kid

Zoe as The Fighting Pug