Michael Thomas Bass (6 July 1799 – 29 April 1884) was a British brewer and member of the British House of Commons. Under his leadership, Bass became the largest brewery in the world and the best known brand in the United Kingdom. Bass represented the Derby constituency in the House of Commons as a member of the Liberal Party between 1847 and 1883 where he was an effective advocate for the brewing industry. He was a generous benefactor of both Derby and Burton upon Trent where his company was based.
The coming of the railway to Burton upon Trent in 1839 helped the growth of the business by reducing transport costs. The company had four agents in the 1830s in London, Liverpool Stoke-on-Trent and Birmingham. By the 1880s, this had grown to 21 in the United Kingdom and another in Paris. The export trade was supplied by the agencies in London and Liverpool.
Under Bass's leadership, company production and sales had grown enormously. Production of ale had grown to 340,000 barrels in 1860 and to almost a million barrels in the late 1870s. By 1881, the company had three breweries and 26 malthouses covering 145 acres in Burton upon Trent. The company was Britain's biggest brewery and was one of its best known companies.
Bass was an orthodox Liberal supporting free trade, low taxes and improving living standards for the working class. He promoted legislation to abolish imprisonment for small debtors. His legislation against organ grinders on the grounds that they were street nuisances was less successful.
He was known as a philanthropist both in Burton upon Trent and Derby. His obituarists claimed that his contributions totalled ₤80,000 and that he had given Derby a new library, School of Art, recreation ground, and swimming baths.
Bass represented Derby until the final years of his life. William Ewart Gladstone offered Bass a peerage which he declined preferring to stay in the House of Commons.