A is the 13th studio album by British rock band Jethro Tull. It was released on 29 August 1980 in the UK and 1 September of the same year in the United States.

The album was initially written and recorded with the intention of being frontman Ian Anderson's debut solo album. Hence the album's title: the master tapes were marked "A" for Anderson during recording. However, the album was eventually released as a Jethro Tull album after pressure from Chrysalis Records. Anderson has since stated that he regrets allowing the album to be released under the Jethro Tull name.

Musically, the album was a departure from prior Tull works, adopting more of an electronic rock sound with heavy use of synthesizers, although still retaining the band's trademark folk influence and Anderson's flute playing. Lyrically, the album saw a similar departure from the fantasy and folklore themes of previous Tull work, instead emphasizing contemporary matters such as the Cold War. The album was the first Tull album released following a large lineup change which saw drummer Barrie "Barriemore" Barlow and keyboardists John Evan and Dee Palmer departing the band in 1980 while bassist John Glascock had died from heart complications the previous year. The album instead features Glascock's touring replacement Dave Pegg on bass in his first recorded appearance with the band, Mark Craney on drums and Eddie Jobson on keyboards (with Jobson credited as a "special guest") and electric violin.