A Night at the Opera is the fourth studio album by the British rock band Queen, released on 21 November 1975 by EMI Records in the United Kingdom and by Elektra Records in the United States. Produced by Roy Thomas Baker and Queen, it was reportedly the most expensive album ever recorded at the time of its release. The album's title is taken from the Marx Brothers film of the same name.
 
A Night at the Opera was recorded at various studios across a four-month period in 1975. Due to management issues, Queen had received almost none of the money they earned for their previous albums. Subsequently, they ended their contract with Trident Studios and did not use their studios for the album (with the sole exception being "God Save the Queen", which had been recorded the previous year). They employed a complex production that extensively used multitrack recording, and the songs incorporated a wide range of styles, such as ballads, music hall, dixieland, hard rock and progressive rock influences. Aside from their usual equipment, Queen also utilised a diverse range of instruments such as a double bass, harp, ukulele and more.
 
Upon release, A Night at the Opera topped the UK Albums Chart for four non-consecutive weeks. It peaked at number four on the US Billboard 200 and became the band's first platinum-certified album in the US. It also produced the band's most successful single in the UK, "Bohemian Rhapsody", which became their first UK number one. Despite being twice as long as the average length of singles during the 1970s, the song became immensely popular worldwide.