Jim Carrey

Mr. Popper

Carla Gugino

Amanda

Angela Lansbury

Mrs. Van Gundy

Ophelia Lovibond

Pippi

Madeline Carroll

Janie

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)