Stefán Karl Stefánsson .... (voice)
Ben Stiller .... Larry Daley
Carla Gugino
Robin Williams .... Theodore Roosevelt
Dick Van Dyke .... Cecil Fredericks
Steve Coogan .... Napoleon
Patrick Gallagher .... Attila the Hun
rest of cast listed alphabetically:
Alex Castillo .... Mayan (voice)
Jake Cherry .... Nick
Martin Christopher .... Lewis
Bill Cobbs
Ian Duffy .... Irish Worker #1
Marshall Factora .... Museum Patron
Pierfrancesco Favino .... Christopher Columbus
Ricky Gervais .... Hippopotamus/Bambi
Matthew Harrison .... Neanderthal Man
Ed Helms .... The Dentist
Erica Jones .... Little girl (voice)
Cohl Klop .... Voice
Jono Lee .... Chinese Worker
Rami Malek .... Ahkmenrah
Mizuo Peck .... Sacagawea
Darryl Quon .... Hun
Kim Raver
Dan Rizzuto .... Neanderthal
Mickey Rooney .... Gus
Paul Rudd
Craig Ricci Shaynak .... Additional Voices (voice)
Lou Torres .... Miguel
Owen Wilson .... Jedidiah