The Universal make-up department submitted two alien designs for consideration by the studio executives. The design that was rejected was saved and then later used as the Mutant in Universal's This Island Earth (1955).

Although credited to Harry Essex, most of the script, including dialogue, is copied almost verbatim from Ray Bradbury's initial film treatment.

This was one of the few American movies from the 1950s to place its credits at the end rather than at the beginning.

According to a magazine article the "bubble" effect seen when the audience is seeing things from the alien's POV was achieved by actually blowing a specially formulated "tough" bubble around the camera lens. These shots were kept short since the bubbles only lasted a brief time.

The first 3-D film to be released by Universal Studios.

In a separately filmed trailer, Richard Carlson talks to the audience about the film and about Three Dimension; animated sequences attempt to illustrate the three dimensional effect.

Typing the helicopter's number into most web search engines will produce its registration and history (last checked in 2013). Although the copter is shown carrying three people in the film, it was registered as a two seat vehicle.

Fantastic Something, a Hellenic pop duo with a minor UK hit in 1983 (If She Doesn't Smile), adopted their name from a line heard in the movie ("That fantastic something!")

According to the tear-off calendar on the wall in the sheriff's office, around 50:00, the climactic day of the movie was "February 11 Saturday". February 11 was one of the actual days of filming, in 1953; however, in that year it fell on a Wednesday. Presumably, the set dresser used an old prop calendar for 1950 or 1939.

"Sand Rock, Arizona" appears to be a fictitious town.

This iconic movie is one of those named in the main theme for The Rocky Horror Picture Show (1975), "Science Fiction / Double Feature".

The specific lyric is: "Then at a deadly pace / It Came From Outer Space / And This is How the Message Ran...."

The registration number assigned to the helicopter now shows (December 2017) that the helicopter was exported to New Zealand, and its registration decertified, in 1959. In 2010, the registration number N189B was reassigned. It now belongs to a fixed-wing, single-engine aircraft.

The shot of the spaceship destroying a ship was in fact a newsreel shot of HMS Balham exploding after being torpedoed in November 1941.

A rarity among science-fiction films in that its alien visitors are neither benevolent nor malevolent but instead seem indifferent to anything with our level of intelligence.

Steven Spielberg has credited this film, and its plot focused on benign alien visitors seemingly uninterested in helping or harming human beings, as the main inspiration for his film Close Encounters of the Third Kind (1977).