Heavy Horses is the eleventh studio album by Jethro Tull, released on 10 April 1978. It is considered the second album in a trilogy of folk-rock albums by Jethro Tull, although folk music's influence is evident on a great number of Jethro Tull releases. The album abandons much of the folk lyrical content typical of the previous studio album, Songs from the Wood (1977), in exchange for a more realist perspective on the changing world. Likewise, the band sound is harder and tighter. The album reached No. 19 on the Billboard 200 album chart, and peaked at No. 20 on the UK Albums Chart. The third album in the folk-rock trilogy is Stormwatch (1979).
This album was the last studio album to feature John Glascock playing bass on all tracks.