| Tom Cruise | Ray Ferrier |
| Dakota Fanning | Rachel Ferrier |
| Miranda Otto | Mary Ann |
| Justin Chatwin | Robbie |
| Tim Robbins | Harlan Ogilvy |
| Rick Gonzalez | Vincent |
| Yul Vazquez | Julio (as Yul Vázquez) |
| Lenny Venito | Manny the Mechanic |
| Lisa Ann Walter | Bartender |
| Ann Robinson | Grandmother |
| Gene Barry | Grandfather |
| David Alan Basche | Tim |
| Roz Abrams | Herself |
| Michael Brownlee | TV Reporter, Osaka |
| Camillia Sanes Monet | News Producer (as Camillia Sanes) |
| Marlon Young | News Cameraman |
| John Eddins | News Van Driver |
| Peter Gerety | Hatch Boss / Load Manager |
| David Harbour | Dock Worker |
| Miguel Antonio Ferrer | Brazilian Neighbor |
| January LaVoy | Brazilian Neighbor's Wife |
| Stephen Gevedon | Neighbor with Lawnmower |
| Julie White | Woman |
| Marianne Ebert | Hysterical Woman (as Marianni Ebert) |
| Rafael Sardina | Mechanic's Assistant |
| Amy Ryan | Neighbor with Toddler |
| Ed Vassallo | Intersection Guy |
| Michael Arthur | Intersection Guy |
| Danny Hoch | Intersection Guy Cop |
| Sharrieff Pugh | Man Studying Street |
| Erika LaVonn | Photographer |
| Christopher Evan Welch | Photographer |
| John Michael Bolger | Man Holding Woman |
| Omar Jermaine | Man Holding Woman |
| Robert Cicchini | Guy in Suit |
| Jim Hanna | Bus Driver |
| Tracy Howe | Crowd Onlooker |
| Adam Lazarre-White | Crowd Onlooker |
| Vito D'Ambrosio | Crowd Onlooker |
| Laura Zoe Quist | Crowd Onlooker |
| Ana Maria Quintana | Crowd Onlooker |
| Lorelei Llee | Crowd Onlooker |
| Mark Manley | Ferry Worker |
| John Scurti | Ferry Captain |
| Becky Ann Baker | Disaster Relief Volunteer |
| Mariann Mayberry | Mother |
| Ty Simpkins | 3 Year Old Boy |
| Jerry Walsh | Smart Guy |
| Tommy Guiffre | National Guardsman |
| Daniel Franzese | National Guardsman |
| Ed Schiff | Older Man |
| Ellen Barry | Woman from Upstate |
| Amy Hohn | Panicky Woman |
| Dan Ziskie | Informative Guy (as Daniel Ziskie) |
| David Conley | Ill-Informed Guy |
| Daniel Eric Gold | Conspiracy Buff |
| Booker T. Washington | Conspiracy Debunker |
| Maggie Lacey | Upset Mother |
| Eric Zuckerman | Doomsday Guy |
| Daniel A. Jacobs | Younger Man |
| Asha R. Nanavati | Woman in Crowd |
| Joaquin Perez-Campbell | Young Soldier in Tank |
| Dendrie Taylor | Well Meaning Mother |
| James DuMont | Well-Meaning Father |
| Travis Aaron Wade | War of the Worlds Soldier |
| Benjamin Ciaramello | War of the Worlds Soldier (as Benny Ciaramello) |
| Ricky Luna | War of the Worlds Soldier |
| Columbus Short | War of the Worlds Soldier |
| Kent Faulcon | War of the Worlds Soldier |
| Kevin Collins | Marine Major |
| Terry Thomas | Marine Major |
| Clay Bringhurst | Airforce Pilot |
| Jorge-Luis Pallo | Army Private |
| Suanne Spoke | Businesswoman |
| Kirsten Nelson | Businesswoman |
| Melody Garrett | Older Woman |
| Lauri Johnson | Older Woman |
| Takayo Fischer | Older Woman |
| Shanna Collins | Teenager |
| Elizabeth Jayne Hong | Teenager |
| Art Chudabala | Man in Basket |
| Jeffrey Hutchinson | Man in Basket |
| Dempsey Pappion | Man in Basket |
| Chris Todd | Man in Basket |
| Johnny Kastl | Boston Soldier |
| Juan Carlos Hernández | Boston Soldier |
| Bruce W. Derdoski Jr. | Boston Soldier |
| John N. Morales | Boston Soldier |
| Morgan Freeman | Narration (voice) |
| Dustin Ardine | |
| Tom Kenny | SpongeBob SquarePants (voice) (archive footage) |
| Lisa Sample | Boston Survivor |
| Amir Allak | Survivor (uncredited) |
| Chad O. Allen | Refugee (uncredited) |
| Michalina Almindo | Refugee (uncredited) |
| Peter Appleseed | Army Soldier (uncredited) |
| Alan Kemper Armani | Survivor (uncredited) |
| Cass Asher | Soldier (uncredited) |
| Claudia Barroso | Portuguese Woman (uncredited) |
| Gerald Blakey | Refugee (uncredited) |
| David Blanc | Chef (uncredited) |
| James Boss | Refugee (uncredited) |
| Felix J. Boyle | Fleeing Businessman (uncredited) |
| J.J. Brewer | Dock Hand #1 (uncredited) |
| Paul Bunnell | Boston Survivor (uncredited) |
| David Campbell | Boston Survivor (uncredited) |
| Josef Cannon | Mike Sims (uncredited) |
| April Crisafulli | Refugee (uncredited) |
| Stella Croxon | Survivor - Mother with Boy (uncredited) |
| Robert DaGasta | Survivor (uncredited) |
| Ambi Daniel | Refugee (uncredited) |
| Crystal Dawne | Starving Girl in Diner (uncredited) |
| Joseph DeBona | Newark Deliveryman (uncredited) |
| Geoffrey DeMarsh | Athens Ferry Passenger (uncredited) |
| Zachary DeMarsh | Athens Ferry Passenger (uncredited) |
| Martin Dew | Looter in Diner (uncredited) |
| Matt DeWinkeleer | Refugee with Cart (uncredited) |
| Ed Easterling | Pure Survivor (uncredited) |
| Sherman T. Edwards Jr. | Lexington Survivor (uncredited) |
| Tom Faulkner | Soldier (uncredited) |
| Robert Feeley | Survivor (uncredited) |
| Pamela Fischer | Neighbor (uncredited) |
| George Fisher | Man Fighting Ray - at Car (uncredited) |
| Charles 'Chaz' Galuski | Ferry Boat Refugee (uncredited) |
| Alan Gary | Portuguese Soccer Player (uncredited) |
| David Gere | Survivor (uncredited) |
| Chuck Gerena | NJ Neighbor - Running (uncredited) |
| Christopher Gilbertson | Additional Voices (voice) (uncredited) |
| Jennifer Glasgow | Survivor (uncredited) |
| Phillip Gramm | Survivor (uncredited) |
| Dave Harrington | Paramedic (uncredited) |
| Takako Haywood | Refugee (uncredited) |
| Christy Lee Hughes | Refugee (uncredited) |
| Dalon Huntington | Survivor (uncredited) |
| Marc A. Hutchins | Army Soldier / Survivor (uncredited) |
| Angie Jaree | Singer (uncredited) |
| Anthony Jennings | Amputee (uncredited) |
| Freddie Johnson | Boston Survivor (uncredited) |
| Ingrid Johnson | Ray's Neighbor (uncredited) |
| Janis Jones | Boston Survivor (uncredited) |
| Vladislav Kozlov | Survivor (uncredited) |
| Bocker T Labradoodle | Extra (uncredited) |
| Dustin LaValley | Soldier (uncredited) |
| Angel Lebon | Cyclist (uncredited) |
| William Todd Levinson | Refugee (uncredited) |
| Laura Lyman | Refugee (uncredited) |
| Robert Mancino | Man on Street (uncredited) |
| Ed Mantell | Soldier (uncredited) |
| Sean Marrinan | Ferry Goer (uncredited) |
| Nicholas Mastromarco | Refugee (uncredited) |
| Riley G. Matthews Jr. | Newark Cop (uncredited) |
| Robin McGee | Survivor (uncredited) |
| Tanda Mercer | Woman in Crowd (uncredited) |
| Emily Nilsen | Survivor (uncredited) |
| Scott Norris | Refugee (uncredited) |
| Robert O'Connor | Homeless Patron (uncredited) |
| Fred Ortiz | Army Soldier / Survivor (uncredited) |
| A.J. Presley | Survivor (uncredited) |
| Angel Princess | Survivor (uncredited) |
| Vincent Rao | Refugee (uncredited) |
| Bill Richards | RB Leaper (uncredited) |
| Rachelle Roderick | Alien Escapee (uncredited) |
| Cory Rodriguez | Army Soldier (uncredited) |
| Dannielle Rose | Ferry Passenger (uncredited) |
| Nicole Signore | Refugee (uncredited) |
| Athena Stamos | Refugee (uncredited) |
| Tracy Lee Staton | Alien invasion survivor (uncredited) |
| Joseph Benjamin Stewart | Small Town Person (uncredited) |
| Channing Tatum | Boy in Church Scene (uncredited) |
| Patrick Tierney | Extra (uncredited) |
| Johnny Torres | Survivor (uncredited) |
| Mark Valinsky | Townsman (uncredited) |
| Michael Waldron | Newark Cop (uncredited) |
| Michael Kevin Walker | Survivor (uncredited) |
| Terry Ward | Army Corporal (uncredited) |
| Stacy Ann Wilkins | Young Mother (uncredited) |
| Mike Yedwab | Highway Driver (uncredited) |
