UFO were an English rock band formed in London in 1968. They became a transitional group between early hard rock and heavy metal and the new wave of British heavy metal. The band's final lineup consisted of vocalist Phil Mogg, lead guitarist Vinnie Moore, rhythm guitarist and keyboardist Neil Carter, bass guitarist Rob De Luca, and drummer Andy Parker. They had gone through several line-up changes, leaving Mogg as the only constant member, and had disbanded three times. The band also featured former Scorpions guitarist and Michael Schenker Group (MSG) founder Michael Schenker, who was a member of UFO from 1973 to 1978 and rejoined the band sporadically between 1993 and 2003, when Moore replaced him. In May 2018, Mogg announced that he would retire from UFO after one last tour as a member of the band in 2019; however, their farewell tour was set to conclude in 2022 before it was cancelled, due to Mogg's health issues. Mogg confirmed UFO's third disbandment in April 2024.

The new wave of British heavy metal was a nationwide musical movement that started in England in the mid-1970s and achieved international attention by the early 1980s. Editor Alan Lewis coined the term for an article by Geoff Barton in a May 1979 issue of the British music newspaper Sounds to describe the emergence of new heavy metal bands in the mid to late 1970s, during the period of punk rock's decline and the dominance of new wave music.