Jim Carrey
Tom Popper
Carla Gugino
Amanda
Angela Lansbury
Mrs. Van Gundy
Ophelia Lovibond
Pippi
Madeline Carroll
Janie Popper
Clark Gregg
Nat Jones
Jeffrey Tambor
Mr. Gremmins
David Krumholtz
Kent
Philip Baker Hall
Franklin
Maxwell Perry Cotton
Billy
James Tupper
Rick
Dominic Chianese
Reader
William Charles Mitchell
Yates
Henry Kelemen
Young Tommy Popper
Kelli Barrett
Tommy's Mom
Dylan Clark Marshall
Young Tommy Popper #2
Brian T. Delaney
Young Tom Popper, Sr. (voice)
Elaine Kussack
Gremmins's Secretary
Harlin C. Kearsley
Town Car Driver
Desmin Borges
Daryl
Lee Moore
Reginald
Dominic Colón
Tito
Jeff Lima
Freddy
Frank Ciornei
Klaus
J.R. Horne
Arnold
Matthew Wolf
Antarctic Friend (voice)
Andrew Stewart-Jones
Animal Control Guy
James Chen
Fish & Game Officer
Rafael Osorio
Marine & Waterfowl Officer
Curtis Shumaker
Sanitation Officer
Joseph D'Onofrio
Random Man on Street
Olga Merediz
Nanny
Betsy Aidem
Tavern Hostess
Angel Caban
Fishmonger
Chris Beetem
Young Developer
Charles L. Campbell
Old Tom Popper, Sr. (voice)
Daniel Stewart Sherman
Zoo Security Guard
Mike Massimino
Cop #1
Charlie Semine
Cop #2 (Quint)
Cynthia Kirchner
Pulse Lounge Beautiful Girl (uncredited)