The Satan Bug is a 1965 American crime science fiction suspense film from United Artists, produced and directed by John Sturges, that stars George Maharis, Richard Basehart, Anne Francis, and Dana Andrews. The screenplay by James Clavell and Edward Anhalt was loosely based on the 1962 novel of the same name by Alistair MacLean, written under the pseudonym Ian Stuart. The film score was composed by Jerry Goldsmith. The film featured the first use of a stabilized camera mount, invented by Nelson Tyler, placed on a helicopter.^[3][4]

Lee Barrett, a former intelligence agent, is approached by a man offering him a job to join a political organization against bioweapons. However, the man turns out to be an impersonator sent by Barrett's former boss, Eric Cavanaugh, to test his loyalty. Cavanaugh asks Barrett to investigate the murder of the security chief and the disappearance of Dr. Baxter, the head scientist at Station Three, a secretive bioweapons laboratory.

Barrett and Cavanaugh arrive at the lab and are advised by Dr. Hoffman to seal the laboratory using concrete. Hoffman reveals that there are two deadly bioweapons inside a strain of botulinus that oxidizes after eight hours and a newly developed virus called the "Satan Bug" that could wipe out all life on Earth. Barrett enters the sealed laboratory and finds Dr. Baxter dead, with the vials containing the "Satan Bug" and botulinus missing.

Barrett receives a mysterious telegram from his former flame, Ann, who is also assigned to work with him on the investigation. They discover the dead body of another scientist from the lab and trace the suspect to Charles Reynolds Ainsley, a reclusive millionaire, and pharmaceutical tycoon. Ainsley threatens to release the viruses unless Station Three is destroyed.

After a demonstration of the botulinus in Florida, Ainsley threatens to release more in Los Angeles County unless the lab is closed. Barrett and Ann follow a lead to an abandoned car and find the missing vials. They are confronted by armed men who take them to Dr. Hoffman's home. Unbeknownst to the henchmen, they are being followed.

At the home, the henchmen realize they are being followed by security agents. In a confrontation at an abandoned gas station, Barrett convinces the henchmen to keep Ann hostage while he escapes the garage, which is set on fire. Barrett stops a passing car driven by Hoffman, who has double-crossed his own men. They strike a deal for the location of the vials in Los Angeles.

As they are intercepted by security agents, Ainsley is arrested, and Barrett realizes the agents are actually Ainsley's security guards. He defeats them and confronts Ainsley again. Ainsley threatens to release the "Satan Bug" but drops it during a struggle. Barrett grabs it while taking control of a helicopter. Ainsley jumps out of the helicopter, and Barrett safely lands.

Meanwhile, Ann and the authorities discover the other vials hidden in the ice of a concession stand at the Los Angeles baseball stadium. Barrett contacts Ann and his superiors, and they safely disarm the bombs. Barrett prepares to land the helicopter, reflecting on how things have come full circle.

• List of American films of 1965