It! The Terror from Beyond Space is an independently made 1958 American science fiction horror film, produced by Robert Kent, directed by Edward L. Cahn, that stars Marshall Thompson, Shawn Smith (Shirley Patterson), and Kim Spalding. The film was distributed by United Artists as a double feature with Curse of the Faceless Man.

The story involves Earth's second mission to Mars to discover the fate of the Challenge 141 and its crew. Only a single survivor is found still alive from that crashed spaceship. The survivor, the expedition's former commander, claims that his crew were killed by a hostile Martian life form. No one from the rescue ship believes him until the creature, now a stowaway, begins hunting the crew on their return trip to Earth.

The film's premise has been cited as an inspiration for screenwriter Dan O'Bannon's screenplay for Ridley Scott's classic 1979 film Alien.