Bass Brewery () was founded in 1777 by William Bass in Burton-upon-Trent, Staffordshire, England. The main brand was Bass Pale Ale, once the highest-selling beer in the UK. By 1877, Bass had become the largest brewery in the world, with an annual output of one million barrels. Its pale ale was exported throughout the British Empire, and the company's iconic red triangle became the UK's first registered trade mark.

Bass took control of a number of other large breweries in the early 20th century. In the 1960s merged with Charrington United Breweries to become the largest UK brewing company, Bass Charrington. The brewing operations of the company were bought by Interbrew (now Anheuser-Busch InBev) in 2000, while the retail side (hotels and pubs) were renamed Six Continents plc. Because at the time Interbrew controlled a large portion of the UK beer market, the Competition Commission instructed Interbrew to sell the Bass brewery along with certain brands to Coors (now Molson Coors), while retaining the rights to the Bass brand. In 2010, it was widely reported that AB-InBev was attempting to sell the rights to the Bass brand in the UK for around £10 million to £15 million.

In the UK, draught Bass (4.4% ABV) has been brewed under contract in Burton by Marston's (formerly a relatively minor competitor) for AB-InBev since 2005, while bottled products are brewed at AB-InBev's own brewery in Samlesbury, Lancashire, for export. Bass is also brewed locally in the United States and Belgium. Bass Ale is a top ten premium canned ale in the UK, with 16,080 hectolitres sold in 2010.