Funktion-One is a British loudspeaker manufacturer based in Royal Dorking, Surrey, England. The company was formed in 1992 by Tony Andrews and John Newsham.

Widely known for their distinctive purple cabinets and white axehead drivers, Funktion-One systems have been popularly employed in notable dance music venues across the globe including Berghain (Berlin), Jaeger (Oslo), Move (Exeter), Link (Bologna), Marquee, Mission and Basement (New York), D-Edge (São Paulo), Circus Afterhours (Montreal), Smartbar (Chicago), Colosseum (Jakarta), De School (Amsterdam), and Savage (Hanoi).

The company was formed in 1992 by Tony Andrews and John Newsham, following their departure from Turbosound - a company focused on sound systems for music festivals they had started in 1978. Following eight years of research and development, Funktion-One completed its first major project - designing and installing a sound system for the Millennium Dome's Central Show. Since then the company has built a reputation in installed sound.

According to Andrews, the company's name spells "funktion" with a "k" as a reference to 1970s funk music.

Funktion-One equipment, installed by Sound Investment Audio, is in use at many music venues in the United States.

2000: Millennium Dome, London, England

Funktion-One were chosen to provide the sound system for the Millennium Dome's Central Show. This was the first official Funktion-One installation, ostensibly the debut of the company's Resolution line of loudspeakers.

2002-2014: Space, Ibiza