Daniel Hansen as Lewis (voice)

Jordan Fry as Lewis (voice)

Wesley Singerman as Wilbur (voice)

Matthew Josten as Michael 'Goob' Yagoobian (voice)

Stephen J. Anderson as Bowler Hat Guy / Grandpa Bud / Tallulah (voice)

Tom Selleck as Cornelius Robinson (voice)

Tom Kenny as Mr. Willerstein (voice)

Laurie Metcalf as Lucille Krunklehorn (voice)

Angela Bassett as Mildred (voice)

Nicole Sullivan as Franny (voice)

Harland Williams as Carl (voice)

John H. H. Ford as Mr. Harrington (voice)

Don Hall as Coach / Gaston (voice)

Paul Butcher as Stanley (voice)

Tracey Miller-Zarneke as Lizzy (voice)

Jessie Flower as Young Franny (voice)

Ethan Sandler as Doris / CEO / Spike / Dmitri / Laszlo / Fritz / Petunia (voice)

Dara McGarry as Mrs. Harrington / Receptionist (voice)

Nathan Greno as Lefty (voice)

Kelly Hoover as Aunt Billie (voice)

Adam West as Uncle Art (voice)

Aurian Redson as Frankie (voice)

Joseph Mateo as T-Rex (voice)

Joe Whyte as Reporter (voice)

Cooper Cowgill as Additional Voices (voice)

Cameron Covell as Additional Voices (voice)

David Cowgill as Additional Voices (voice)

Makenna Cowgill as Additional Voices (voice)

Terri Douglas as Additional Voices (voice)

Jackie Gonneau as Additional Voices (voice)

Mick Hazen as Additional Voices (voice)

Shannon O'Connor as Additional Voices (voice)

Jordan Orr as Additional Voices (voice)

Lynwood Robinson as Additional Voices (voice)

Grace Rolek as Additional Voices (voice)

Greyson Spann as Additional Voices (voice)

Krista Swan as Additional Voices (voice)

Fred Tatasciore as Additional Voices (voice)