Stand Up is the second studio album by the British rock band Jethro Tull, released in 1969. Before recordings for the album began, the band's original guitarist Mick Abrahams resigned because of musical differences with Ian Anderson; Abrahams wanted to stay with the blues rock sound of their 1968 debut, This Was, while Anderson wished to add other musical influences such as folk rock. He was replaced by guitarist Martin Barre, who appeared on every Jethro Tull album from this point on.
Stand Up represents the first album project on which Anderson was in full control of the music and lyrics. The result was an eclectic album with various styles appearing in its songs, yet an album which remained somewhat in the blues rock mould, which would be the last such album from Jethro Tull.
The album quickly went to number 1 in the UK charts, while the non-album single "Living in the Past" rose to number 3.