Queen II is the second studio album by the British rock band Queen. It was released on 8 March 1974 by EMI Records in the UK and Elektra Records in the US. It was recorded at Trident Studios and Langham 1 Studios, London, in August 1973 with co-producers Roy Thomas Baker and Robin Geoffrey Cable, and engineered by Mike Stone. It is significant for being the first album to contain many elements of the band's signature sound of multi-layered overdubs, vocal harmonies, and varied musical styles.

Described as "arguably the heaviest Queen album", Queen II marked the end of the first phase of the band's career. The album combines a heavy rock sound with art rock and progressive rock elements, and has been called "a pillar of grandiose, assaultive hard rock" by the Rock and Roll Hall of Fame. Queen II is not a concept album but a collection of songs with a loose theme running throughout. The two sides of the original LP were labelled "Side White" and "Side Black" (instead of the conventional sides A and B), with corresponding photos of the band dressed in black on the front cover and white on the inner gatefold. The white side has songs with a more emotional theme and the black side is almost entirely about fantasy, often with quite dark themes. Mick Rock's cover photograph was frequently re-used by the band throughout its career, including the music videos for the songs "Bohemian Rhapsody" (1975) and "One Vision" (1985).

Released to an initially mixed critical reception, Queen II remains one of the band's lesser-known albums. Nonetheless, it has retained a cult following since its release, and garnered praise from critics, fans, and fellow musicians alike.

Led Zeppelin and the Who are probably in Queen II somewhere, because they were among our favourite groups, but what we are trying to do differently from either of those groups [is] this sort of layered sound. The Who had the open chord guitar sound... but our sound is more based on the overdriven guitar sound... I also wanted to build up textures behind the main melody lines. We were trying to push studio techniques to a new limit for rock groups – it was fulfilling all our dreams, because we didn't have much opportunity for that on the first album.

Queen performed their first gig on 27 June 1970, but did not finish their self-titled debut album, Queen, until November 1972. In the interim, the band had developed other, more complex material but elected to wait to record it until they had more freedom and experience in the studio. "Father To Son", "Ogre Battle" and "Procession" had all been premiered as early as 1972. "Seven Seas of Rhye" dated to Freddie Mercury's Wreckage days in 1969. "See What a Fool I've Been", the B-side to the "Seven Seas of Rhye" single and "White Queen (As It Began)" were left over from the Smile days. "Stone Cold Crazy", also from Mercury's Wreckage period, had been in the set list for years, but was held back and reworked for the third album, Sheer Heart Attack. Portions of "The Prophet's Song" were also rehearsed during the Queen II sessions, but the song was not completed until the fourth album, A Night at the Opera. Queen insisted that Trident Studios allow them to record at regular hours instead of studio down-time, as they had for the first album. The band approached David Bowie to produce, but he declined because he was then recording Pin Ups and working on songs for Diamond Dogs. Robin Geoffrey Cable, with whom Mercury had worked during the "I Can Hear Music" session, was asked to produce "Nevermore" and "Funny How Love Is", and collaborate with Roy Thomas Baker on the ambitious "March of the Black Queen".

After the commercial failure of the single "Keep Yourself Alive" from the first album, Queen decided it needed a single that did not take "too long to happen" (i.e., without a lengthy guitar intro). "Seven Seas of Rhye", recorded with the specific intention of being the album's leading single, began in a way designed to grab attention. Rehearsals for the Queen II sessions commenced on or around 26 July. (Due to management problems, the first album was finally released as the band prepared to record Queen II.) During these rehearsals, the band were interviewed by Melody Maker and told the magazine that their new album would have a theme of "good versus evil". The band also ended its collaboration with John Anthony, who had co-produced the first album, due to clashes between Mercury and Anthony. On 3 August, the band performed at a gig in Newcastle, then returned to London for a pre-recording rehearsal on 4 August. Sessions began on 5 August with takes 1–12 of the finished version of "Seven Seas of Rhye". On 6 August, they started recording "Father To Son", working on takes 1–4. They continued to work on the album until 9 August, when they made promotional videos for "Keep Yourself Alive" and "Liar" from the debut album.

According to the August 11 issue of Record Mirror, the band was scheduled to go back into the studio on 15 August. However, David Bowie and Ken Scott were producing Pin Ups in the studio Queen had been using. The band were put into Studio 2, with producer Robin Geoffrey Cable. Although this studio only had an 8-track tape machine at the time, Queen decided to work on backing tracks nonetheless. Takes of Nevermore were recorded that day, and Funny How Love Is was recorded on 16 August. Queen had to cancel a studio session on 17 August to perform a gig in Peterborough. They returned to London around 3:00 a.m. Roy Thomas Baker had also left (around 12–18 August) to work with a Danish client named Gasolin', who were recording their album Gasolin' 3. On 18 August, Queen, Baker and Cable recorded the complex backing track for "The March Of The Black Queen". After taking a break for a bank holiday, the band began principal overdubbing on 28 August. Some backing tracks had to be cut into separate multi-tracks because of the extensive overdubbing. (The album's working title became "Over The Top" in reference to overdubbing.) During this period, John Deacon had to do his summer exams. In September, Brian recorded "Procession," which had its live premiere on 13 September when the band played at the Golders Green Hippodrome in London. (This was also their first recorded concert.)

On 24 September the band did their first radio interview with Bob Harris. In early October, Queen met with photographer Mick Rock for the first time to discuss album concept art. They took a short break starting on 12 October to begin a promotional tour around Europe. On 18 October, the band returned to London to continue work on the album. On 3 November, Queen had their first publicity shoot with Mick Rock, producing the album's iconic cover image. Queen took another break from recording in November to tour with Mott The Hoople. Rehearsals began on 5 November and the tour started in Blackburn on 13 November. The band would come near London a few times in early December, and popped into the studio on their days off. The tour ended at the Hammersmith Odeon on 14 December, followed by a standalone gig at Leicester University on 15 December. Rough mixing for the album commenced on 17 December. Martin Hayman of Sounds visited the band on 22 December while they were finishing rough mixes for "Loser In The End", "Ogre Battle", and "The Fairy Feller's Master-Stroke".