The 1940s were the decade when World War II occurred, and the impacts of the war evoked economic expansion and advances in science and technology, including, films, television, and more. The era produced classic films which included mostly concepts of war, and the style of Film Noir became more popular with its combined themes of crime dramas and dark imagery. The genre of science fiction also rose in popularity with its envisioned impacts of an actual or imagined scientific event occurring among society or individuals. Sci-fi includes sub-genres of fantasy, horror, superhero fiction, cyberpunk, anthropological science fiction, the dying earth, gothic fiction, and more. Although the definition is disputed among authors, critics, scholars, and readers, the genre was influential in literature, film, and television.

The sci-fi genre incorporates concepts of innovative, futuristic science, technology, space observation, time travel, parallel universes, extraterrestrials, sentient artificial intelligence, cybernetics, immortality and the singularity. Sci-fi explores the potential consequences of scientific, social, and technological innovations and evokes wonder while providing entertainment and may criticize current society and explore alternatives. Popular 1940s sci-fi movies included Man Made Monster (1941), Flash Gordon Conquers the Universe (1940), Dr. Cyclops (1940), Black Friday (1940), One Million B.C. (1940), The Devil Commands (1941), The Invisible Man Returns (1940), House of Dracula (1945), House of Frankenstein (1945), and Dr. Jekyll and Mr. Hyde (1941). From accolades, ratings, reviews, popularity, and impact, including details about the film, awards and more, here are the best sci-fi movies of the 1940s, ranked.

Related: Highest Grossing Science Fiction Movies of All Time

10 Man Made Monster (1941)

man made monster
Universal Pictures

Man Made Monster is a science-fiction horror film distributed in March 1941 and created for Universal Pictures by George Waggner and Jack Bernhard, starring Lon Chaney Jr. and Lionel Atwill. Cast performances also included Anne Nagel, Frank Albertson, Samuel S. Hinds, Ben Taggart, Chester Gan, Frank O'Connor, and Russell Hicks. The film is about a tragic accident involving a bus colliding with a power line, killing all the passengers except Dan McCormick, who survives because he is immune to electricity. The plot resembles The Invisible Ray (1936), The Walking Dead (1936), and Indestructible Man (1956). The film was re-released under the titles Electric Man and The Mysterious Dr. R., The Atomic Monster in 1953, and as a double feature with The Flying Saucer in 1950.

9 Flash Gordon Conquers the Universe (1940)

Flash Gordon Conquers the Universe (1940)
Universal Pictures

Flash Gordon Conquers the Universe is a science fiction serial movie with 12-chapters which was distributed by Universal Pictures, co-directed by Ford Beebe, Ray Taylor, and produced by Henry MacRae. The serial was written by George H. Plympton, Basil Dickey, and Barry Shipman, and adapted from comic strips of the same name created by Alex Raymond from King Features Syndicate. Cast performances included Buster Crabbe, Carol Hughes, Charles B. Middleton, Frank Shannon, Roland Drew, and more. The plot involves a deadly plague called the Purple Death, which is caused by Ming the Merciless, whose spaceships spread "Death Dust" into Earth's atmosphere. The complete serial received nominations for the 1940 Retro Hugo Award’s Best Dramatic Presentation - Long Form in 2016, sponsored by The World Science Fiction Society.

Related: Flash Gordon Remake Is Now Live-Action, Taika Waititi Is Writing the Script

8 Dr. Cyclops (1940)

dr cyclops
Paramount Pictures

Dr. Cyclops is a science fiction horror film distributed in 1940 by Paramount Pictures, which was produced by Dale Van Every, Merian C. Cooper, and directed by Ernest B. Schoedsack. The film included cast performances by Thomas Coley, Victor Kilian, Janice Logan, Charles Halton, Frank Yaconelli, Albert Dekker, and more. Dr. Cyclops is the first American horror film made in full, three-strip Technicolor, featuring elaborate sets with special effects, and Schoedsack was adamant about making the color effects appear believable. The film earned Oscar nominations at the 13th Academy Award for Best Visual Effects by Farciot Edouart and Gordon Jennings. It was also adapted into a novelette by Henry Kuttner, and released on DVD in 2007 by Universal Studios Home Entertainment included in The Classic Sci-Fi Ultimate Collection Vol. 2.

7 Black Friday (1940)

black friday
Universal Pictures

Black Friday is a horror science fiction film distributed by Universal Pictures in 1940, which was directed by Arthur Lubin, with the screenplay written by Curt Siodmak and Eric Taylor. The film’s cast included Boris Karloff, Bela Lugosi, Stanley Ridges, Anne Nagel, Anne Gwynne, Virginia Brissac, Edmund MacDonald, Paul Fix, Murray Alper, and Gonzalo Meroño. The film is about Dr. Ernest Sovac, who is taken for execution and relays his story to a reporter as he approaches the electric chair. Black Friday was released on DVD in “The Bela Lugosi Collection" in September 2005. The film won the Saturn Award for Best DVD Collection for Murders in the Rue Morgue, The Black Cat , The Raven and The Invisible Ray included in "The Bela Lugosi Collection".

6 One Million B.C. (1940)

one million b.c.
United Artists

One Million B.C. is a fantasy science fiction film distributed by United Artist, directed and produced by Hal Roach Studios, starring Victor Mature, Carole Landis, and Lon Chaney Jr. It has also been colorized. The film is about a group of hikers who get caught in a storm and seek shelter in a cave, where they discover prehistoric carvings conveying a young caveman’s story. Footage from the film was stored in a stock footage library, and later used by various companies and producers to save money on special effects in films that featured dinosaurs. The film developed the technique of displaying optically enlarged lizards and baby crocodiles as dinosaurs, which was used by many films that followed it, and was deemed “slurpasaur” by fans.

5 The Devil Commands (1941)

the devil commands
Columbia Pictures

The Devil Commands is a horror science fiction film distributed by Columbia Pictures in 1941, and directed by Edward Dmytryk, written by Robert Hardy Andrews, Milton Gunzburg, and William Sloane. The film features cast performances by Boris Karloff, Richard Fiske, Amanda Duff, Anne Revere, Ralph Penney, Dorothy Adams, Walter Baldwin, Kenneth MacDonald, and Shirley Warde. The plot involves a doctor who is researching human brain waves, when the unexpected death of his wife provokes him to become obsessed with communicating with her using his experiments. He captures her brain waves on his machine and searches for a receptor to prove electric currents in the human brain remain sustainable after death. The story is an adaptation of the novel The Edge of Running Water by Sloan.

Related: Best Sci-fi Horror Movies of the 2020s

4 The Invisible Man Returns (1940)

The Invisible Man Returns
Universal Pictures

The Invisible Man Returns is a horror science fiction film distributed by Universal Pictures in 1941, which was created by Joe May, Lester K. Cole, Curt Siodmak, and Cedric Belfrage. The film stars Cedric Hardwicke, Vincent Price, Nan Grey, John Sutton, and includes cast performances by Cecil Kellaway, Alan Napier, Forrester Harvey, and Paul England. The film is the second installment of the Invisible Man film series, which is a sequel to the film The Invisible Man released in 1933. The film involves a man being wrongly convicted of murder, and begging a doctor for an injection of invisibility serum that will drive him mad. The film received an Oscar nomination for the special effects by John P. Fulton, Bernard B. Brown and William Hedgcock.

3 House of Dracula (1945)

house of dracula
Universal Pictures

House of Dracula is a horror sci-fi film distributed by Universal Pictures in 1945, created by Erle C. Kenton, Edward T. Lowe, George Bricker, Dwight V. Babcock, and Paul Malvern. The film takes place at the castle of Dr. Franz Edelmann, who is visited by Count Dracula and the Wolf Man, who seek a cure for their vampirism and lycanthropy. Lowe incorporated into the plot elements of the script for Wolf Man vs. Dracula with Frankenstein's monster, and many cast members from House of Frankenstein performed in House of Dracula. The film stars Lon Chaney, Martha O'Driscoll, John Carradine, Lionel Atwill, Onslow Stevens, Glenn Strange, Jane Adams, and Ludwig Stossel. The film also features properties of Universal Horror from the film House of Frankenstein.

2 House of Frankenstein (1945)

house of frankenstein
Universal Pictures 

House of Frankenstein is a horror sci-fi film distributed by Universal Pictures in 1945, created by Erle C. Kenton, Paul Malvernwith, and written by Edward T. Lowe, based on The Devil's Brood by Curt Siodmak. The film features cast performances by Boris Karloff, Lon Chaney Jr., John Carradine, J. Carrol Naish, Glenn Strange, Anne Gwynne, Peter Coe, Lionel Atwill, George Zucco, Elena Verdugo, and more. The film is about Dr. Gustav Niemann, who escapes from prison and promises his assistant Daniel that he will create a new body for him. They murder Professor Lampini and take control of his sideshow involving the corpse of Count Dracula, Frankenstein's monster and The Wolf Man, which were preserved in the castle, and Niemann plots to revive Frankenstein's monster.

1 Dr. Jekyll and Mr. Hyde (1941)

Dr. Jekyll and Mr. Hyde (1941)
Loews Cineplex Entertainment

Dr. Jekyll and Mr. Hyde is a horror sci-fi film distributed by Loew’s Inc. in 1941, created by Victor Fleming, and written by John Lee Mahin, Percy Heath, and Samuel Hoffenstein. The film was created based on the Strange Case of Dr. Jekyll and Mr. Hyde by Robert Louis Stevenson. The cast included Spencer Tracy, Ingrid Bergman, Lana Turner, Donald Crisp, Ian Hunter, Barton MacLane, C. Aubrey Smith, Peter Godfrey, and Sara Allgood, among others. The film takes place in 1887 in London, where Dr. Henry Jekyll is conducting research experiments developed to possibly separate the good from the evil found in one’s human nature. The film received nominations for Academy Awards in the categories of Best Cinematography, Best Film Editing, and Best Music Scoring.