Mr. Popper
Amanda
Mrs. Van Gundy
Pippi
Janie
Nat Jones
Mr. Gremmins
Kent
Franklin
Billy
Rick
Reader
Yates
Young Tommy Popper
Tommy's Mom
Young Tommy Popper #2
Young Tom Popper, Sr. (voice)
Gremmins's Secretary
Town Car Driver
Daryl
Reginald
Tito
Freddy
Klaus
Arnold
Antarctic Friend (voice)
Animal Control Guy
Fish & Game Officer
Marine & Waterfowl Officer
Sanitation Officer
Random Man on Street
Nanny
Tavern Hostess
Fishmonger
Young Developer
Old Tom Popper, Sr. (voice)
Zoo Security Guard
Cop #1
Cop #2 (Quint)
Pulse Lounge Beautiful Girl (uncredited)