Hemispheres is the sixth studio album by Canadian rock band Rush, released in October 1978 by Anthem Records. After touring to support the band's previous release, A Farewell to Kings, during which the group gained popularity in the UK, Rush started work on their next album. As with the band's previous studio album, Hemispheres was recorded at Rockfield Studios in Monmouthshire and Trident Studios in London with longtime engineer and arranger, Terry Brown. Rush continued its progressive rock sound with the side-long "Cygnus X-1 Book II: Hemispheres" and the nine-minute instrumental "La Villa Strangiato", which was the band's first instrumental piece.

Rush was a Canadian rock band that primarily comprised Geddy Lee, Alex Lifeson (guitar) and Neil Peart. The band formed in Toronto in 1968 with Lifeson, drummer John Rutsey, and bass guitarist/vocalist Jeff Jones, whom Lee immediately replaced. After Lee joined, the band went through several line-up changes before arriving at its classic power trio line-up with the addition of Peart in July 1974, who replaced Rutsey four months after the release of their self-titled debut album; this line-up remained intact for the remainder of the band's career.