The main organ at St Edmundsbury Cathedral was built by Harrison & Harrison of Durham in 2010. The earlier organ (Nicholson, 1970) had been assembled with parts of previous instruments, including Norman and Beard (1914) and Walker (1864). After many years of excellent service, it had become very unreliable, out of date, and unable to fulfil a role at the centre of the worshipping and artistic life of the Cathedral.

The new instrument was used for the first time on Advent Sunday 2010, with an inaugural concert series taking place over the course of 2011. It has four manuals and 59 speaking stops, with over 3,500 pipes. The deepest pipes are 32 feet in length, while those that produce the highest sounds are a fraction of an inch in diameter. The majority of the pipework is new, although some material from the previous instruments has been retained after thorough overhaul, cleaning, and re-voicing.

The organ is situated in a chamber overlooking the North Transept and the Quire. It has two magnificent cases containing pipes from the Great and Choir divisions. These were decorated according to a scheme by the architect John Bucknall based on an original design of Alan Rome, and painted by Campbell Smith & Co in the Lady Chapel over the course of 2010. The cases include motifs from the highly decorated ceilings in the Cathedral, and complete the East end of the cathedral as envisioned in the 1960s building work