Kevin Costner
Kenneth O'Donnell

Bruce Greenwood
John F. Kennedy

Steven Culp
Robert F. Kennedy

Dylan Baker
Robert McNamara

Michael Fairman
Adlai Stevenson

Henry Strozier
Dean Rusk

Frank Wood
McGeorge Bundy

Kevin Conway
Gen. Curtis LeMay

Tim Kelleher
Ted Sorensen

Len Cariou
Dean Acheson

Bill Smitrovich
Gen. Maxwell Taylor

Shawn Driscoll
U-2 Pilot

Stephanie Romanov
Jacqueline Kennedy

Lucinda Jenney
Helen O'Donnell

Caitlin Wachs
Kathy O'Donnell

Jon Foster
Kenny O'Donnell, Jr.

Bruce Thomas
Floyd

Dakin Matthews
Arthur Lundahl

Colette O'Connell
Kenny's Assistant #2

Karen Ludwig
Operator Margaret

Audrey Rapoport
White House Operator #1

Marliese Schneider
White House Operator #2

Ed Lauter
Gen. Marshall Carter

James Karen
George Ball

Dan Ziskie
Gen. Walter 'Cam' Sweeney

Peter White
John McCone

Kelly Connell
Pierre Salinger

Olek Krupa
Andrei Gromyko

Ilya Baskin
Anotoly Dobrinyn

Timothy Jerome
Journalist

Jack McGee
Richard J. Daley

John Aylward
Orville Dryfoos

Madison Mason
Adm. George Anderson

Christopher Lawford
Cmdr. William B. Ecker

David O'Donnell
Lt. Bruce Wilhemy

Benjamin Koldyke
RF-8 Pilot

Ruben Moreno
Argentine Diplomat

Thomas Roberts
Sonar Operator

Michael Gaston
Captain of USS Pierce

J. Tucker Smith
Captain of USS Kennedy

Chris Henry Coffey
Officer of Destroyer

Oleg Vidov
Valerian Zorin

Alex Veadov
Radio Room Operator #3

Jack Blessing
John Scali

Tom Everett
Walter Sheridan

Karl Makinen
Young FBI Agent

Boris Lee Krutonog
Alexander Fomin

Charles Esten
Maj. Rudolf Anderson

Allan Graf
Football Referee

Robert Miranda
RFK's Driver

Todd Sible
RFK's Staffer

Cliff Fleming
Aerial Coordinator

Craig Hosking
Pilot

Greg Bronson
Secret Service Agent (uncredited)

Walter Cronkite
Self (archive footage) (uncredited)

Ryder Davis
Boy Scout (uncredited)

Armen Garo
Crewman on Freighter (uncredited)

Phil Hawn
UN Administrator (uncredited)

Rick Kain
Carpenter (uncredited)

John F. Kennedy
Self (voice) (archive footage) (uncredited)

Pramod Kumar
U Thant (uncredited)

Richard Rossi
Reporter (uncredited)

Brad Yoder
Sorensen's Assistant (uncredited)