Broderick Crawford as J. Edgar Hoover

James Wainwright as Young Hoover

Michael Parks as Robert F. Kennedy

José Ferrer as Lionel McCoy

Celeste Holm as Florence Hollister

Rip Torn as Dwight Webb

Dan Dailey as Clyde Tolson

Ronee Blakley as Carrie DeWitt

Howard Da Silva as Pres. Franklin D. Roosevelt

John Marley as Dave Hindley

Michael Sacks as Melvin Purvis

Raymond St. Jacques as Martin Luther King

June Havoc as Hoover's Mother

Lloyd Nolan as Attorney General Harlan Stone

Andrew Duggan as Pres. Lyndon B. Johnson

Jack Cassidy as Damon Runyon

George Plimpton as Quentin Reynolds

Lloyd Gough as Walter Winchell

William Jordan as Pres. John F. Kennedy

Brad Dexter as Alvin Karpis

George D. Wallace as Senator Joseph McCarthy

Henderson Forsythe as Suydam

Fred J. Scollay as Putnam

William Wellman Jr. as Dwight Webb Sr.

Ellen Barber as Janice Harper

Art Lund as Benchley

Mary Alice Moore as Miss Bryant

Jim Antonio as Senator Kenneth McKellar

Gregg Abels as President's Aide

Dan Resin as President's Advisor

James Dixon as Reilly

Penny du Pont as Newscaster

Alvin Miles as Valet

John Bay as Heywood Brown

Brooks Morton as Earl Warren

Richard M. Dixon as The President

James Dukas as Frank

Ron Faber as Hijacker

Sam Chew Jr. as FBI Agent

Paul Thomas as FBI Agent

Ken Harvey as FBI Agent

Jack Drummond as FBI Agent

Colin Bremner as FBI Agent

Dana Rowe as FBI Agent

Hanns Manship as FBI Agent

Ed Nast as FBI Agent

Tanya Roberts as Stewardess

Margo Lynn Curtis as Stewardess

Larry Pine as Kelly

John Stefano as Harry Brunette

Jennifer Lee Pryor as Ethel Brunette

Gwyn Gilliss as Mary Jo Kopechne (voice)

Bruce Weitz as Voice on Tape

Wyman Kane as Senator Markum

Gordon Zimmerman as Louis Lepke

Marty Lee as Mafia Man

Reno Carrel as Dillinger

Frank Rohrbach as White House Aide

Marshall Bordon as White House Aide

Joe Mayo as White House Aide

Joe ArrowSmith as Newspaper Man