Celestion is a British maker of loudspeakers.

The work of what would become Celestion started in Hampton Wick (suburban London) in 1924. Celestion Radio Company and Celestion Limited were formed in 1927, and two years later the company moved across the Thames to Kingston. The company grew rapidly, but was hit by the depression. Wartime restrictions forced Celestion and the nearby company British Rola to produce loudspeakers to the same specification; British Rola bought Celestion in 1947 and moved production to Thames Ditton a year later. The name of the resulting company was Rola Celestion; that of its products, Celestion. (MPP, later a camera maker, was formed as a subsidiary during the war.)

Production of radio, television and "hi fi" speakers continued in the postwar years. In 1968 the company started production in Ipswich, moving all production there by 1975. The company merged with a clothing company in 1970 and the result was named Celestion Industries, which in turn became Celestion International in 1979.

In 1992 the loudspeaker part of the business was sold to Kinergetics Holdings, which also bought KEF.

Today Celestion International and KEF form GP Acoustics UK. In 2006 Celestion ceased to manufacture pro audio finished systems and now completely focus on the manufacture of guitar, bass guitar and pro audio drivers.

The Celestion SL600 was considered to represent a revolution in loudspeaker design when it first appeared, combining a case made from rigid honeycomb aluminium material with drive units designed using laser interferometry and impulse response testing. The result was a particularly colouration-free sound, which remains hard to beat to this day. Independent test results show the exceptionally flat frequency response obtained from this small speaker, which uses a sealed enclosure that makes it well suited to precise bass equalisation. Most speakers today are bass reflex designs that roll off more rapidy beyond their resonance.

The Celestion Blue can claim place as the world’s first dedicated guitar loudspeaker. The 1950s witnessed the emergence of a new breed of musician – the electric guitarist – and Celestion responded to their needs for a rugged, reliable loudspeaker by modifying a standard "G12" radio speaker. The unique tonal character of what came to be known as the Celestion Blue, combined with the valve amps of the time, helped to define the electric guitar as we know it today. It was rapidly adopted by pioneers of rock & roll and popular music throughout the late 50s and early 60s.

• Company history