Charlie Hunnam as Raleigh Becket

Rinko Kikuchi as Mako Mori

Idris Elba as Stacker Pentecost

Max Martini as Herc Hansen

Clifton Collins Jr. as Tendo Choi

Ron Perlman as Hannibal Chau

Charlie Day as Dr. Newton Geiszler

Burn Gorman as Dr. Hermann Gottlieb

Robert Kazinsky as Chuck Hansen

Robert Maillet as Lt. Aleksis Kaidanovsky

Heather Doerksen as Lt. Sasha Kaidanovsky

Larry Joe Campbell as Tommy T

Brad William Henke as Miles

Diego Klattenhoff as Yancy Becket

Santiago Segura as Wizened Man

Jane Watson as Raleigh and Yancy's Mom

Jung-Yul Kim as Hannibal Chau Thug

Joshua Peace as Officer

Mana Ashida as Young Mako

Joe Pingue as Captain Merrit

Milton Barnes as McTighe

Brian Frank as 1st Officer

Ellen McLain as Gipsy Danger AI (voice)

David Fox as Old Man on Beach

Jake Goodman as Child

Robin Thomas as American UN Representative

Julian Barnes as British UN Representative

David Richmond-Peck as Canadian UN Representative

Sebastian Pigott as Engineer

J.C. Kenny as TV Reporter

Robert Morse as Raleigh and Yancy's Dad

Mike Chute as Saltchuck Crew

Duncan McLeod as Saltchuck Crew

Louis Paquette as Saltchuck Crew

Matthew G. Taylor as Saltchuck Crew

Frank Nakashima as UN Representative

Terry Belleville as UN Representative

Farzad Sadrian as UN Representative

Mishu Vellani as UN Representative

Clive Walton as UN Representative

Peter Kosaka as Young Mako's Father

Yiren Stark as Young Mako's Mother

Mark Luu as Wei Tang Triplet

Charles Luu as Wei Tang Triplet

Lance Luu as Wei Tang Triplet

William S. Wong as Engineer (uncredited)

Victoria Sawal as Chinese Girl in Anti-Kaiju Refuge

Timothy Gibbs as Marine (uncredited)

Hugh Tran as Asian Boy

Scott Martin Gershin as Kaiju Sound Effects (voice) (uncredited)