Leonardo DiCaprio character John Edgar Hoover
Josh Hamilton character Robert Irwin
Geoff Pierson character Mitchell Palmer
Armie Hammer character Clyde Tolson
Naomi Watts character Helen Gandy
Judi Dench character Anna Marie Hoover
Gunner Wright character Dwight Eisenhower
Kaitlyn Dever character Palmer's Daughter
Adam Driver character Walter Lyle
Ed Westwick character Agent Smith
Jessica Hecht character Emma Goldman
Josh Lucas character Charles Lindbergh
Dermot Mulroney character Colonel Schwarzkopf
Denis O'Hare character Albert Osborne
Lea Thompson character Lela Rogers
Damon Herriman character Bruno Hauptmann
Sadie Calvano character Edgar's Niece
Amanda Schull character Anita Colby
Roberta Bassin character Roosevelt's Secretary
Emily Alyn Lind character Shirley Temple
Barbara Keegan character Bombing Witness
Gerald Downey character FBI Agent
Jeffrey Donovan character Robert Kennedy
Geoff Stults character Raymond Caffrey
Thomas Langston character Young Boy
Lea Coco character Agent Sisk
Aaron Lazar character Prosecutor Wilentz
Cheryl Lawson character Palmer's Wife
Brady Matthews character Inspector
David A. Cooper character Franklin Roosevelt
Kelly Lester character Head Secretary
Jack Donner character Edgar's Father
Dylan Burns character Hoover as a Child
Jack Axelrod character Caminetti
Michael James Faradie character Bureau Agent (1919)
Josh Stamberg character Agent Stokes
Christian Clemenson character Inspector Schell
Billy Smith character Secret Service Officer
Ken Howard character Harlan Fiske Stone
Zach Grenier character John Condon
Johnny Cicco character Young Agent
Steve Monroe character Restaurant Host
Stephen Root character Arthur Koehler
Gary Werntz character Attorney General
David Clennon character Senator Friendly
Michael O'Neill character Senator McKellar
Eric Larkin character Fred Hunter
Eric Frentzel character William Mahan
Kyle Eastwood character Stork Club Band
Gregory Hoyt character Agent One
Jenny Phagan character Baker's Wife
Chris Caputo character Bronx Baker
Shannon McClain Robertson character African American Woman (as Shannon McClain)
Leslie Augustine character Lindbergh Nanny (uncredited)
Fileena Bahris character Starlet (uncredited)
Emily Banks character Radical Citizen (uncredited
Jennipher Foster character Lucille Ball (uncredited)
Belinda Gosbee character Gangster's Moll (uncredited)
Elizabeth Karr character Secretary (uncredited)
Martin Luther King character Self (archive footage) (uncredited)
Lindsay Lucas-Bartlett character Hollywood Starlet (uncredited)
Pat Nixon character Self (archive footage) (uncredited)
Richard Nixon character Self (archive footage) (uncredited)
Jamie Noel character Racetrack Gambler (uncredited)
