Circus of Horrors is a 1960 British horror film directed by Sidney Hayers, and starring Anton Diffring, Yvonne Monlaur, Erika Remberg, Kenneth Griffith, Jane Hylton, Conrad Phillips, Yvonne Romain, and Donald Pleasence. Set in 1947, it follows a deranged plastic surgeon who changes his identity after botching an operation, and later comes to gain control of a circus that he uses as a front for his surgical exploits. The original screenplay was written by American screenwriter George Baxt.

It was released in the United States by American International Pictures as a double feature with The Angry Red Planet.

In 1947 England, plastic surgeon Dr. Rossiter is wanted by police after performing a botched operation on socialite Evelyn Morley. However, believing himself to have brilliant abilities as a surgeon, he and his assistants, Martin and Angela, evade capture and escape to France. To avoid capture, Rossiter changes his name to Dr. Schüler. Schüler sees a girl scarred in the recent war, Nicole, and befriends her father, a circus owner named Vanet. Schüler performs a surgical procedure on Nicole to restore her face. Schüler then suggests to Vanet that they become partners; Vanet will sign the circus over to Schüler, who will pay all the bills, but they will have a private document to show it still belongs to Vanet. Vanet realises that the doctor is on the run from something or someone, and wants a place to hide out in, but is glad to repay him in any way he can, and also hopes to save his circus. Drunk from his celebration, Vanet tries to dance with the bear that is part of his act, but drops a bottle which injures the animal, who starts to maul him. He screams instructions to the surgeon about how to control the bear; at first Schüler runs to help, then realises his opportunity, and leaves Vanet to die. With the assistance of Martin and Angela, Schüler begins to recruit performers, seeking out lowly and disfigured criminals whom he offers to transform with surgery should they join him. In Paris, he encounters prostitute Elissa Caro robbing and killing a man in an alleyway. Schüler offers to transform Elissa's face—which is marked by a large scar—and provide her a new identity as a performer in his circus. She reluctantly agrees.

A decade later, Schüler's circus is a prominent act throughout Europe, touted for its aesthetically beautiful performers. When its members choose to leave, however, they meet a series of mysterious accidents. One performer, Magda von Meck, informs Schüler she wants to leave. During her farewell performance in Berlin, Magda is killed during a knife-throwing act, deliberately orchestrated by Schüler. Magda's death motivates a jealous Elissa to regain top-billing in the circus act. Later, Schüler is approached by Melina, a woman whose face has been disfigured by acid, and agrees to perform surgery on her with the intent of turning her into his new star performer. He soon falls in love with her, and intends to marry her.

Nicole, still performing in the circus, is met by Inspector Arthur Ames, posing as a journalist investigating the deaths that have occurred within the troupe. When he gains Nicole's trust, she confesses that, during her childhood, she underwent an operation from Schüler, whom she believes to be her uncle. Meanwhile, Elissa deduces that Schüler's real name is Rossiter, and attempts to blackmail him with this knowledge into restoring her top-billing in the circus. In retaliation, Schüler sets a python loose in Elissa's caravan, but she remains unwavering. Shortly after, Schüler has Elissa killed during a rope-swinging act, causing her to fall to her death.

When Schüler is attacked by one of his gorillas, he instructs Angela and Martin to perform his own procedures on him. Later, Evelyn Morley, now married to Edward Finsbury, visits the circus. When she meets Schüler, whose face is half-bandaged, she faints. Angela and Martin insist they go into hiding, believing that Evelyn has recognized Schüler, but he insists the show must go on. During a lion taming act, Melina is mauled to death, traumatizing Schüler. As the guests flee in the melee, Evelyn insists to Nicole and Inspector Ames that Schüler and Rossiter are in fact the same man. Meanwhile, a deranged Schüler attacks Angela and Martin in their caravan, stabbing Angela to death. Martin eludes him, and sets a gorilla loose to attack Schüler. Police arrive, and Martin recounts the murders Schüler has committed. Meanwhile, Schüler escapes the gorilla, and attacks Inspector Ames and Nicole, before leading police on a chase through the circus grounds. He is stopped by Evelyn, who deliberately strikes him with her car. As he lay dying, Schüler's last word is "Melina."

The film opened theatrically in London on 8 April 1960.^[1]

In the United States, the film was distributed by American International Pictures as a double feature with A Bucket of Blood (1959), opening in Los Angeles in May 1960.^[2]

In his book A Heritage of Horror (1971, the film critic David Pirie considered Circus of Horrors to be the third entry in what he calls Anglo-Amalgamated's "Sadian trilogy" - the previous films in this conceptual trilogy being Horrors of the Black Museum and Peeping Tom - : three films that focus on sadism, cruelty and violence (with sexual undertones) as opposed to the supernatural horror of the Hammer films in the same era.