The symphonic organ is a style of pipe organ that flourished during the first three decades of the 20th century in town halls and other secular public venues, particularly in the United States and the United Kingdom. It has roots in 19th-century Europe, and is a variation of the classical pipe organ. It features expanded capabilities, with many pipes imitative of orchestral instruments, and with multiple expressive divisions and organ console controls for seamlessly adjusting volume and tone, generally with electric organ actions and winding. These expansions let the organist approximate a conductor's power to shape the tonal textures of Romantic music and orchestral transcriptions. These organs are generally concert instruments as opposed to church organs. The symphonic organ has seen a revival in the US, Europe and Japan, particularly since the 1980s.

Henry Willis & Sons is a British firm of pipe organ builders founded in 1845. Although most of their installations have been in the UK, examples can be found in other countries.