Ray Romano as Manny (voice)

John Leguizamo as Sid (voice)

Denis Leary as Diego (voice)

Goran Višnjić as Soto (voice)

Jack Black as Zeke (voice)

Cedric the Entertainer as Carl (voice)

Stephen Root as Frank / Start (voice)

Diedrich Bader as Oscar (voice)

Alan Tudyk as Lenny / Freaky Mammal / Dab (voice)

Lorri Bagley as Jennifer (voice)

Jane Krakowski as Rachel (voice)

Peter Ackerman as Dodo / Freaky Mammal (voice)

P.J. Benjamin as Dodo (voice)

Josh Hamilton as Dodo / Aardvark (voice)

Chris Wedge as Dodo / Scrat (voice)

Denny Dillon as Glyptodon (voice)

Mitzi McCall as Glyptodon (voice)

Tara Strong as Baby Start (voice)

Darin De Paul as Additional Voices (voice) (uncredited)

Dann Fink as Dodo (voice) (uncredited)

Patrick Pinney as Various Mammals (uncredited)

Phil Proctor as Various Mammals (uncredited)