Tannoy was founded in London in 1926 by Guy R. Fountain as Tulsemere Manufacturing Company. The name Tannoy was developed as a syllabic abbreviation of tantalum alloy, the material used in the company's electrolytic rectifier. The company changed its name to Tannoy in 1928 and trademarked the name in 1932.

The company gained recognition throughout the 1930s due to their loudspeaker systems and audio components, but it wasn't until the Second World War that their public address systems became popular. By 1946, the brand name 'Tannoy' had become synonymous with public address systems and was added to the Oxford English Dictionary.

Over the following decades, the company continued to develop successful audio equipment. In 1974, Guy R. Fountain retired and the company was acquired by Harman International Industries. In 1976, the company relocated to Coatbridge, Scotland from London. In 1987, Tannoy merged with Goodmans to become Tannoy Goodmans International. This was then acquired in 2002 by TC Electronic to form the TC Group. Today, Tannoy is still widely used in music production.