William Henry Pratt (Camberwell, 23 november 1887 — Midhurst, 2 februari 1969) was een Engels acteur die bekend is geworden onder zijn artiestennaam Boris Karloff.

Pratt zou diplomaat worden en studeerde in Londen. Hij emigreerde echter in 1909 naar Canada en sloot zich onder de naam Boris Karloff aan bij een theatergezelschap. Zij toerden een decennium lang door de Verenigde Staten, totdat Karloff in Hollywood terechtkwam. Hij had op dat moment nauwelijks bekendheid en geen geld. Om inkomen te vergaren speelde Karloff in 80 (merendeels stomme) films, voordat hij in 1931 uitgekozen werd voor de rol van monster in Frankenstein. Er werd onmiddellijk een zweem van mysterie rond Karloff gecreëerd, door hem op de aftiteling slechts te vermelden als "?". Karloff zou de rol van monster, met de bekende bouten in zijn nek, nog tweemaal spelen in Bride of Frankenstein en Son of Frankenstein, en om deze rol wordt hij het meest herinnerd.

Karloff stond bekend als een sympathiek mens, met veel vrienden zowel in als buiten het filmvak. Hij was gek op kinderen en bracht verschillende opnamen van kinderverhalen uit.

Filmografie 

|-
| 1918 || The Lightning Raider || ? ||
|-
| 1919 || The Masked Rider || Mexicaanse bruut in saloon || 
|-
| || His Majesty, the American || Spion || 
|-
| || The Prince and Betty || ? ||
|-
| 1920 || The Deadlier Sex || Jules Borney || 
|-
| || The Courage of Marge O'Doone || Tavish || Verloren film
|-
| || The Last of the Mohicans || Indiaan || Onvermeld
|-
| 1921 || Without Benefit of Clergy || Ahmed Khan ||
|-
| || Cheated Hearts || Nil Horned || Verloren film
|-
| || The Cave Girl || Baptiste || Verloren film
|-
| 1922 || The Altar Stairs || Hugo || Waarschijnlijk verloren film
|-
| || The Woman Conquers || Raoul Maris || 
|-
| 1923 || The Gentleman from America || ? || Onvermeld. Waarschijnlijk verloren film
|-
| || The Prisoner || Prins Kapolski || Verloren film
|-
| 1924 || Riders of the Plains || ? ||
|-
| || The Hellion || De bandiet ||
|-
| || Dynamite Dan || Tony Garcia ||
|-
| 1925 || The Prairie Wife || Diego || Verloren film
|-
| || Lady Robinhood || Cabraza || Verloren film
|-
| 1926 || The Greater Glory || Scissors Grinder || Verloren film
|-
| || The Eagle of the Sea || Piraat || Onvermeld
|-
| || Flames || Blackie Blanchett || 
|-
| || Flaming Fury || Gaspard || 
|-
| || The Man in the Saddle || Overvaller || Verloren film
|-
| 1927 || Tarzan and the Golden Lion || Ozawa || 
|-
| || The Meddlin' Stranger || Al Meggs ||
|-
| || The Princess from Hoboken || Pavel || Verloren film
|-
| || The Phantom Buster || Ramon ||
|-
| || Two Arabian Knights || De purser || 
|-
| 1928 || Burning the Wind || Pug Doran || Verloren film
|-
| || Vultures of the Sea || Grouchy || Verloren film
|-
| || The Little Wild Girl || Maurice Kent || 
|-
| 1929 || The Devil's Chaplain || Boris || 
|-
| || The Fatal Warning || Mullins || Verloren film
|-
| || The Phantom of the North || Jules Gregg || Verloren film
|-
| || Two Sisters || Cecil || Verloren film
|-
| || Behind That Curtain || Soedanese bediende || Eerste geluidsfilm
|-
| || The King of the Kongo || Macklin / Martin || 
|-
| || The Unholy Night || Abdoul ||
|-
| 1930 || The Sea Bat || Corsicaan || 
|-
| || The Utah Kid || Baxter || 
|-
| 1931 || The Criminal Code || Ned Galloway ||
|-
| || King of the Wild || Mustapha || 
|-
| || Young Donovan's Kid || Cokey Joe ||
|-
| || Smart Money || Sport Williams ||
|-
| || The Public Defender || Professor || 
|-
| || I Like Your Nerve || Luigi || 
|-
| || Graft || Joe Terry || 
|-
| || The Mad Genius || Fedor's vader ||
|-
| || The Guilty Generation || Tony Ricca ||
|-
| || Frankenstein || Monster van Frankenstein || Vermeld als ? / KARLOFF
|-
| 1932 || Behind the Mask || Jim Henderson ||
|-
| || Business and Pleasure || Sjeik ||
|-
| || Scarface || Gaffney ||
|-
| || The Miracle Man || Nikko || 
|-
| || Night World || "Happy" MacDonald ||
|-
| || The Old Dark House || Morgan || Vermeld als KARLOFF
|-
| || The Mask of Fu Manchu || Dr. Fu Manchu || 
|-
| || The Mummy || Imhotep/Ardath Bey || Vermeld als KARLOFF
|-
| 1933 || The Ghoul || Professor Morlant || 
|-
| 1934 || The Lost Patrol || Sanders ||
|-
| || The House of Rothschild || Graaf Ledrantz ||
|-
| || The Black Cat || Hjalmar Poelzig || Vermeld als KARLOFF
|-
| 1935 || Bride of Frankenstein || Monster van Frankenstein || Vermeld als KARLOFF
|-
| || The Raven || Edmond Bateman || Vermeld als KARLOFF
|-
| || The Black Room || Baron Gregor de Berghmann / Anton de Berghmann || 
|-
| 1936 || The Invisible Ray || Dr. Janos Rukh || Vermeld als KARLOFF
|-
| || The Walking Dead || John Ellman ||
|-
| || Juggernaut || Victor Sartorius ||
|-
| || The Man Who Changed His Mind || Dr. Laurence || 
|-
| || Charlie Chan at the Opera || Gravelle ||
|-
| 1937 || Night Key || Dave Mallory || Vermeld als KARLOFF
|-
| 1938 || The Invisible Menace || Mr. Jevries a.k.a. Dolman ||
|-
| || Mr. Wong, Detective || James Lee Wong ||
|-
| 1939 || Devil's Island || Dr. Charles Gaudet || 
|-
| || Son of Frankenstein || Monster van Frankenstein || 
|-
| || The Mystery of Mr. Wong || James Lee Wong ||
|-  
| || Mr. Wong in Chinatown || James Lee Wong ||
|-
| || The Man They Could Not Hang || Dr. Henryk Savaard ||
|- 
| || Tower of London || Mord de beul ||
|-
| 1940 || The Fatal Hour || James Lee Wong ||
|-
| || British Intelligence || Valdar || a.k.a. "Enemy Agent"
|-
| || Black Friday || Dr. Ernest Sovac ||
|-
| || The Man with Nine Lives || Dr. Leon Kravaal ||
|-
| || Doomed to Die || James Lee Wong ||
|-
| || Before I Hang || Dr. John Garth ||   
|-
| || The Ape || Dr. Bernard Adrian ||
|-
| 1941 || The Devil Commands || Dr. Julian Blair ||
|-
| 1942 || The Boogie Man Will Get You || Prof. Nathaniel Billings || 
|-
| 1944 || The Climax || Dr. Hohner || 
|-
| || House of Frankenstein || Dr. Gustav Niemann ||
|-
| 1945 || The Body Snatcher || John Gray || 
|-  
| || Isle of the Dead || Generaal Nikolas Pherides ||
|-
| 1946 || Bedlam || Meester George Sims ||
|-
| 1947 || The Secret Life of Walter Mitty || Dr. Hollingshead ||
|-
| || Lured || Charles van Druten || 
|-
| || Unconquered || Stamhoofd Guyasuta || 
|-
| || Dick Tracy Meets Gruesome || Gruesome || 
|-
| 1949 || Abbott and Costello Meet the Killer, Boris Karloff || Swami Talpur
|-
| 1951 || The Strange Door || Voltan ||
|-
| 1952 || Colonel March Investigates || Kolonel March ||
|-
| || The Black Castle || Dr. Meissen ||
|-
| 1953 || Abbott and Costello Meet Dr. Jekyll and Mr. Hyde || Dr. Henry Jekyll / Mr. Hyde
|-
| 1957 || Voodoo Island || Dr. Phillip Knight || 
|-
| 1958 || The Haunted Strangler || James Rankin || 
|-
| || Frankenstein 1970 || Baron Victor von Frankenstein ||
|-
| || Corridors of Blood || Dr. Thomas Bolton ||
|-
| 1963 || Black Sabbath || Gorca/verteller ||
|-
| || The Terror || Baron von Leppe/Eric ||
|-
| || The Raven || Dr. Scarabus ||
|-
| || The Comedy of Terrors || Amos Hinchley ||
|-
| 1965 || Die, Monster, Die! || Nahum Witley ||
|-
| 1966 || The Ghost in the Invisible Bikini || Hiram Stokely ||
|-
| || Dr. Seuss' How the Grinch Stole Christmas! || The Grinch / verteller || Stemrol, tv-special
|-
| 1967 || The Venetian Affair || Vaugiroud ||
|-
| || Mad Monster Party? || Baron Boris von Frankenstein || Stemrol
|-
| || The Sorcerers || Professor Marcus Monserrat ||
|-
| 1968 || Targets || Byron Orlok ||
|-
| || Curse of the Crimson Altar || Professor John Marsh ||
|-
| || Fear Chamber || Dr. Carl Mandel ||
|-
| || House of Evil || Matthias Morteval ||
|-
| 1970 || Cauldron of Blood || Franz Badulescu || Postume release na Karloffs dood
|-
| 1971 || The Incredible Invasion || Prof. John Mayer || Postume release na Karloffs dood
|-
| || Isle of the Snake People || Carl van Molder / Damballah || Postume release na Karloffs dood
|}

Literatuur 
Donald F. Glut: The Frankenstein Legend. A Tribute to Mary Shelley and Boris Karloff. Scarecrow Press, Metuchen NJ 1973, ISBN 0-8108-0589-8
Paul M. Jensen: Boris Karloff and His Films. A.S. Barnes, South Brunswick 1974, ISBN 0-498-01324-3
Cynthia Lindsay: Dear Boris. The Life of William Henry Pratt A.K.A. Boris Karloff. Limelight Editions, London 1995, ISBN 0-87910-106-7
Scott Allen Nollen: Boris Karloff. A Critical Account of His Screen, Stage, Radio, Television and Recording Work. Mit einem Vorwort von Ray Bradbury). McFarland and Company, Jefferson N.C. 1991, ISBN 0-89950-580-5
 Scott Allen Nollen, Sara Jane Karloff: Boris Karloff. A Gentleman's Life. Midnight Marquee Press, Baltimmore 1999, 2005 (heruitgave), ISBN 1-887664-23-8

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Brits filmacteur
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