Sylvia

Carroll Baker

as Sylvia: West (Karoki, Kay, Carlyle)

George Maharis

as Alan Macklin

Joanne Dru

as Jane (Bronson) Phillips

Peter Lawford

as Frederic Summers

Viveca Lindfors

as Irma Olanski

Edmond O'Brien

as Oscar Stewart

Aldo Ray

as Jonas Karoki

Ann Sothern

as Mrs. Argona / Grace Argona

Lloyd Bochner

as Bruce Stamford III

Paul Gilbert

as Lola Diamond

Jay Novello

as Father Gonzales

Nancy Kovack

as Big Shirley

Gene Lyons

as Gavin Cullen

Anthony Caruso

as Wilbur (aka "Muscles")

Alan Carney

as Gus

Shirley O'Hara

as Mrs. Karoki

Ricky Allen

as Herbert, the Boy in the Library (uncredited)

Val Avery

as Pudgey Smith (uncredited)

Majel Barrett

as Anne (uncredited)

Jean Del Val

as Maitre'd (uncredited)

Connie Gilchrist

as Molly Banter (uncredited)

Gavin Gordon

as Butler (uncredited)

Clive Halliday

as Calligraphy Professor (uncredited)

John Harmon

as Sid (uncredited)

Stacy Harris

as Mr. Leland (uncredited)

Kathleen Mulqueen

as Assistant Principal (uncredited)

Manuel Padilla Jr.

as Pancho Guzman (uncredited)

Robert Random

as (uncredited)

Gene Roth

as Professor Eglebert (uncredited)

Geraldine Wall

as Clerk at Private Hospital (uncredited)

Paul Wexler

as Peter Memel (uncredited)