"Phenomenon" is the third studio album by the English rock band UFO, released in May 1974. It marked the band's first album with guitarist Michael Schenker, who replaced Mick Bolton.
As UFO's debut with major label Chrysalis Records, Phenomenon was also their first release in the United States. With Schenker's arrival, the band shifted away from their blues-based space rock sound to a more straightforward hard rock style. Schenker described the creative process for the track "Rock Bottom," explaining how it began as a riff during rehearsals and evolved with contributions from the band, particularly vocalist Phil Mogg.
The album was produced by Leo Lyons, the bassist of Ten Years After, and all tracks were recorded at Morgan Studios in London. The cover design and photos were created by Hipgnosis.
The album's influence extended to other artists, notably British heavy metal band Iron Maiden, who covered "Doctor Doctor" as the b-side of their "Lord of the Flies" single in 1995 and included it in their Eddie's Archive boxed set collection in 2002.
