John Smith/Number Four

Alex Pettyfer

Henri

Timothy Olyphant

Sarah Hart

Dianna Agron

Number Six / Maren Elizabeth

Teresa Palmer

Mogadorian Commander

Kevin Durand

Sam

Callan McAuliffe

Mark James

Jake Abel

Mr. Simms

Garrett M. Brown

Sherriff James

Jeff Hochendoner

Nicole

Emily Wickersham

Kevin

Patrick Sebes

Number 3

Greg Townley

Number 3's Guardian

Reuben Langdon

Receptionist

Molly McGinnis

Frank

Brian Howe

Bret

Andrew Owen

Girl on Street

Sophia Caruso

Bret

Andy Owen

Sam's Stepdad

Charles Carroll

Mr. Behrman

L. Derek Leonidoff

Physics Teacher

Sabrina de Matteo

Sarah's Dad

Cooper Thornton

Sarah's Mom

Judith Hoag

Sarah's Brother

Jack Walz

Demented Farmer

Bill Laing

Drew

Beau Mirchoff

Kern

Cody Johns

Teen at Party

Isabella Robbins

MOG Warrior

Damien Walters

MOG Warrior

Jon Braver

MOG Warrior

Kevin Cassidy

MOG Warrior

Matt Leonard

MOG Warrior

Nash Edgerton

MOG Warrior

Carrick O'Quinn

MOG Warrior

Tim Sitarz

MOG Warrior

Steve Upton

Tuck (uncredited)

Tucker Albrizzi

Supermarket Cashier (uncredited)

Megan Follows

Sheriff Deputy (uncredited)

Andre' Mason

News Reporter (uncredited)

Brenna Roth

Teen #1 (uncredited)

Morgan Wolk

Neighbor (uncredited)

Jackson Nunn