Charlton Heston as Stewart Graff

Ava Gardner as Remy Royce-Graff

George Kennedy as Sgt. Lew Slade

Lorne Greene as Sam Royce

Geneviève Bujold as Denise Marshall

Richard Roundtree as Miles Quade

Marjoe Gortner as Jody

Barry Sullivan as Dr. Willis Stockle

Lloyd Nolan as Dr. James Vance

Victoria Principal as Rosa Amici

Walter Matthau as Drunk

Monica Lewis as Barbara

Gabriel Dell as Sal

Pedro Armendáriz Jr. as Chavez

Lloyd Gough as Bill Cameron

John Randolph as Los Angeles Mayor

Kip Niven as Walter Russell

Scott Hylands as Asst. Caretaker

Tiger Williams as Corry

Donald Moffat as Dr. Harvey Johnson

Jesse Vint as Buck

Alan Vint as Ralph

Lionel Johnston as Hank

John Elerick as Carl Leeds

John S. Ragin as Chief Inspector

George Murdock as Colonel

Don Mantooth as Sid

Michael Richardson as Sandy

Alex Brown as Pool Player

Bob Cunningham as Dr. Frank Ames

John Dennis as Brawny Foreman

Gene Dynarski as Dam Caretaker

Bob Gravage as Farmer Mr. Griggs

H.B. Haggerty as Pool Player

Tim Herbert as Las Vegas Man

Dave Morick as Technician

Ines Pedroza as Laura

Josh Albee as Boy with Radio (uncredited)

Benjie Bancroft as Citizen (uncredited)

Buzz Barbee as Restaurant Patron (uncredited)

Joan Blair as Pawnbroker's Wife (TV version) (uncredited)

Hal Bokar as Dam Workman (uncredited)

Reb Brown as Young Man on Motorcycle (uncredited)

Vivian Brown as Woman (uncredited)

Ian Bruce as Officer Scott (Wilson Plaza) (uncredited)

Polly Burson as Earthquake Survivor (uncredited)

William H. Burton Jr. as Stranger (uncredited)

Ric Carrott as National Guardsman (uncredited)

David S. Cass Sr. as Sherriff Merle (uncredited)

Lonny Chapman as LAPD Captain (uncredited)

Sam Chew Jr. as Tony (Kathie's Husband) (uncredited)

Shannon Christie as Dr. Vance's Nurse (uncredited)

Erik Cord as Office Worker (uncredited)

Caitanya Dasi as Hare Krishna (uncredited)

Cinmayi Devi as Hare Krishna (uncredited)

Ken DuMain as Earthquake Survivor in Wilson Plaza (uncredited)

Brent Dunsford as Man Drinking from Plastic Cup in Wilson Plaza (uncredited)

Patty Elder as Blonde Secretary in Royce Building (uncredited)

Kenny Endoso as Bar Cook (uncredited)

Jeannie Epper as Blonde Woman (uncredited)

Dotty Ertel as Earthquake Survivor (uncredited)

Bobby Ferro as Sports Car Thief (uncredited)

Bruce M. Fischer as Man (uncredited)

Sig Frohlich as Doctor (uncredited)

James W. Gavin as Helicopter Pilot (uncredited)

Ernest Harada as Seismologist (uncredited)

Jerry Hardin as Man (uncredited)

Bob Harks as Man Fleeing Movie Theatre (uncredited)

Orwin C. Harvey as Man on the Balcony of a Falling House (uncredited)

Lars Hensen as Citizen (uncredited)

Diana Herbert as Woman (uncredited)

Bert Kramer as Policeman (uncredited)

Paul LeClair as National Guardsman (uncredited)

Karl Lukas as Man (uncredited)

Ernesto Molinari as Citizen (uncredited)

Stevie Myers as Earthquake Victim (uncredited)

Jimmy Nickerson as Seismology Graduate Student (uncredited)

Stuart Nisbet as Man on Loudspeaker (voice) (uncredited)

Frances Osborne as Housewife (uncredited)

Grant Owens as Police Officer (uncredited)

Charlie Picerni as Pool Player (uncredited)

Tony Regan as Man Fleeing Movie Theatre (uncredited)

Leoda Richards as Emergency Soup Kitchen Worker in Wilson Plaza (uncredited)

Clark Ross as Man in Outer Office (uncredited)

George Sawaya as Deputy Sherriff (uncredited)

Mark Sawtelle as Boy (uncredited)

Fred Scheiwiller as Jay the Bartender (uncredited)

Debralee Scott as Kathie (TV version) (uncredited)

Dean Smith as Pool Player (uncredited)

Eddie Smith as Citizen (uncredited)

Norman Stevans as Radio Station Technician (uncredited)

Arthur Tovey as Citizen (uncredited)

John Tuell as Prop Tractor Driver (uncredited)

Dick Tufeld as Opening Narrator (uncredited)

Kitty Vallacher as Grocery Store Clerk (uncredited)

Keith Walker as Man on the Radio (voice) (uncredited)

Sandy Ward as Studio Guard (uncredited)

Rick Warick as Office Worker (uncredited)

Dick Warlock as Diver at Hollywood Reservoir (uncredited)

William Whitaker as Ambulance Driver (uncredited)

Don Wilbanks as Dam Workman with Blowtorch (uncredited)

Forrest Wood as Man (uncredited)

Clint Young as Dam Workman (uncredited)