Attack of the 50 Foot Woman is a 1958 independently made American science fiction horror film directed by Nathan H. Juran (credited as Nathan Hertz) and starring Allison Hayes, William Hudson and Yvette Vickers. It was produced by Bernard Woolner. The screenplay was written by Mark Hanna, and the original music score was composed by Ronald Stein. The film was distributed in the United States by Allied Artists as a double feature with War of the Satellites.

The Allied Artists television version runs 75 minutes instead of 66, including a long printed crawl at the beginning and end, repeated sequences, and hold-frames designed to optically lengthen the film's running time.

The film's storyline concerns the plight of a wealthy heiress whose close encounter with an enormous alien in his round spacecraft causes her to grow into a giantess, complicating her marriage which is already troubled by a philandering husband.

Attack of the 50 Foot Woman is a variation on other 1950s science fiction films that featured size-changing humans: The Amazing Colossal Man (1957), its sequel War of the Colossal Beast (1958), and The Incredible Shrinking Man (1957); in this case, a woman is the protagonist. The film's popularity and cult status has spawned numerous parodies and homages in popular media.