Dolby Laboratories, Inc. (often shortened to Dolby Labs) is an American company specializing in audio noise reduction and audio encoding/compression. Dolby licenses its technologies to consumer electronics manufacturers.

Dolby Labs was founded by American Ray Dolby (1933–2013) in London, United Kingdom in 1965. He moved the company headquarters to the United States (San Francisco, California) in 1976 The first product Dolby Labs produced was the Dolby 301 unit which incorporated Type A Dolby Noise Reduction, a compander based noise reduction system. These units were intended for use in professional recording studios.

Dolby was persuaded by Henry Kloss of KLH to manufacture a consumer version of his noise reduction. Dolby worked more on companding systems and introduced Type B in 1968.

Dolby also sought to improve film sound. As the corporation's history explains:

The first film with Dolby sound was A Clockwork Orange (1971), which used Dolby noise reduction on all pre-mixes and masters, but a conventional optical sound track on release prints. Callan (1974) was the first film with a Dolby-encoded optical soundtrack. In 1975, Dolby released Dolby Stereo, which included a noise reduction system in addition to more audio channels (Dolby Stereo could actually contain additional center and surround channels matrixed from the left and right). The first film with a Dolby-encoded stereo optical soundtrack was Lisztomania (1975), although this only used an LCR (Left-Center-Right) encoding technique. The first true LCRS (Left-Center-Right-Surround) soundtrack was encoded on the movie A Star Is Born in 1976. In less than ten years, 6,000 cinemas worldwide were equipped to use Dolby Stereo sound. Dolby reworked the system slightly for home use and introduced Dolby Surround, which only extracted a surround channel, and the more impressive Dolby Pro Logic, which was the domestic equivalent of the theatrical Dolby Stereo.

Dolby developed a digital surround sound compression scheme for the cinema. Dolby Stereo Digital (now simply called Dolby Digital) was first featured on the 1992 film Batman Returns. Introduced to the home theater market as Dolby AC-3 with the 1995 laserdisc release of Clear and Present Danger, the format did not become widespread in the consumer market, partly because of extra hardware that was necessary to make use of it, until it was adopted as part of the DVD specification. Dolby Digital is now found in the HDTV (ATSC) standard of the United States, DVD players, and many satellite-TV and cable-TV receivers. Dolby developed a digital surround sound compression scheme for TV series The Simpsons.

On February 17, 2005, the company became public, offering its shares on the New York Stock Exchange, under the symbol DLB. On March 15, 2005, Dolby celebrated its fortieth anniversary at the ShoWest 2005 Festival in San Francisco.

On January 8, 2007, Dolby announced the arrival of Dolby Volume at the International Consumer Electronics Show. It enables users to maintain a steady volume while switching through channels or program elements (i.e., loud TV commercials).

On June 18, 2010, Dolby introduced Dolby Surround 7.1, and set up theaters worldwide with 7.1 surround speaker setups to deliver theatrical 7.1 surround sound. The first film to be released with this format was Pixar's Toy Story 3 which was later followed by 50 releases using the format. As of April 2012, there are 3,600 Dolby Surround 7.1 movie theaters.

In April 2012, Dolby introduced its Dolby Atmos, a new cinematic technology adding overhead sound, first applied in Pixar's motion picture Brave. In July 2014, Dolby Laboratories announced plans to bring Atmos to home theater. The first television show to use the technology on disc was Game of Thrones.

On February 24, 2014, Dolby acquired Doremi Labs for $92.5 million in cash plus an additional $20 million in contingent consideration that may be earned over a four-year period.

Over the years Dolby has introduced several surround sound systems. Their differences are explained below.