Jethro Tull were a British rock group, formed in Luton, Bedfordshire, in December 1967. Initially playing blues rock, they later incorporated elements of progressive rock, hard rock and folk rock into their music. The band were led by vocalist/flautist/guitarist Ian Anderson, and have included other significant members such as guitarist Martin Barre, drummer Doane Perry, and bassist Dave Pegg.

The group achieved commercial success in 1969 with the album Stand Up, which reached No. 1 in the UK charts, and they toured regularly in the UK and the US. The musical style shifted in the direction of progressive rock with the albums Aqualung, Thick as a Brick and A Passion Play, and shifted again to hard rock mixed with folk rock with Songs from the Wood and Heavy Horses. Jethro Tull have sold over 60 million albums worldwide, with 11 gold and five platinum albums among them. They have been described by Rolling Stone as "one of the most commercially successful and eccentric progressive rock bands".