Kevin Costner as Kenneth O'Donnell

Bruce Greenwood as John F. Kennedy

Steven Culp as Robert F. Kennedy

Dylan Baker as Robert McNamara

Michael Fairman as Adlai Stevenson

Henry Strozier as Dean Rusk

Frank Wood as McGeorge Bundy

Kevin Conway as Gen. Curtis LeMay

Tim Kelleher as Ted Sorensen

Len Cariou as Dean Acheson

Bill Smitrovich as Gen. Maxwell Taylor

Shawn Driscoll as U-2 Pilot

Drake Cook as Mark O'Donnell

Stephanie Romanov as Jacqueline Kennedy

Lucinda Jenney as Helen O'Donnell

Caitlin Wachs as Kathy O'Donnell

Jon Foster as Kenny O'Donnell, Jr.

Matthew Dunn as Kevin O'Donnell

Kevin O'Donnell as NPIC Photo Interpreter

Janet Coleman as Evelyn Lincoln

Bruce Thomas as Floyd

Dakin Matthews as Arthur Lundahl

Liz Sinclair as Kenny's Assistant #1

Colette O'Connell as Kenny's Assistant #2

Karen Ludwig as Operator Margaret

Audrey Rapoport as White House Operator #1

Marliese Schneider as White House Operator #2

Ed Lauter as Gen. Marshall Carter

Walter Adrian as Lyndon Johnson

James Karen as George Ball

Dan Ziskie as Gen. Walter 'Cam' Sweeney

Peter White as John McCone

Kelly Connell as Pierre Salinger

Olek Krupa as Andrei Gromyko

Ilya Baskin as Anotoly Dobrinyn

Timothy Jerome as Journalist

Jack McGee as Richard J. Daley

Lamar Smith as Aide

John Aylward as Orville Dryfoos

Madison Mason as Adm. George Anderson

Vivien Straus as White House Aide

Christopher Lawford as Cmdr. William B. Ecker

David O'Donnell as Lt. Bruce Wilhemy

Gene Del Bianco as Petty Officer

Benjamin Koldyke as RF-8 Pilot

Daniel Vergara as OAS Secretary General José A. Mora

Ruben Moreno as Argentine Diplomat

Thomas Roberts as Sonar Operator

Sean Bergin as Chief Sonarman

Alan Francis Sullivan as Executive Officer of USS Pierce

Robert Munstis as Radio Room Operator #1

Michael Gaston as Captain of USS Pierce

Joseph Repoff as Radio Room Operator #2

J. Tucker Smith as Captain of USS Kennedy

Chris Henry Coffey as Officer of Destroyer

Oleg Vidov as Valerian Zorin

Radu Gavor as Romanian Delegate

Zitto Kazann as Chilean Delegate

Alex Veadov as Radio Room Operator #3

Jack Blessing as John Scali

Tom Everett as Walter Sheridan

Karl Makinen as Young FBI Agent

Boris Lee Krutonog as Alexander Fomin

Charles Esten as Maj. Rudolf Anderson

Charles Barrett as Air Force NCO

Darryl Smith as Football Coach

Allan Graf as Football Referee

Robert Miranda as RFK's Driver

Todd Sible as RFK's Staffer

Marya Kazakova as Soviet Woman

Cliff Fleming as Aerial Coordinator

Craig Hosking as Pilot

Michael R. Bowman as Aide to JFK (uncredited)

Greg Bronson as Secret Service Agent (uncredited)

Walter Cronkite as Self (archive footage) (uncredited)

Ryder Davis as Boy Scout (uncredited)

Roger Ferreira as Army Lieutenant General (uncredited)

Armen Garo as Crewman on Freighter (uncredited)

Gilley Grey as Air Force Pilot (uncredited)

Phil Hawn as UN Administrator (uncredited)

Rick Kain as Carpenter (uncredited)

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

Steven Koller as White House Staff (uncredited)

Pramod Kumar as U Thant (uncredited)

Richard Rossi as Reporter (uncredited)

Larry Strauss as Treasury Secretary Douglas Dillon (uncredited)

Brad Yoder as Sorensen's Assistant (uncredited)