The Lunar Society of Birmingham was a British dinner club and informal learned society of prominent figures in the Midlands Enlightenment, including industrialists, natural philosophers and intellectuals, who met regularly between 1765 and 1813 in Birmingham. At first called the Lunar Circle, "Lunar Society" became the formal name by 1775. The name arose because the society would meet during the full moon, as the extra light made the journey home easier and safer in the absence of street lighting. The members cheerfully referred to themselves as "lunaticks", a contemporary spelling of lunatics. Venues included Erasmus Darwin's home in Lichfield, Matthew Boulton's home, Soho House, Bowbridge House in Derbyshire, and Great Barr Hall.

Matthew Boulton was an English businessman, inventor, mechanical engineer, and silversmith. He was a business partner of the Scottish engineer James Watt. In the final quarter of the 18th century, the partnership installed hundreds of Boulton & Watt steam engines, which were a great advance on the state of the art, making possible the mechanisation of factories and mills. Boulton applied modern techniques to the minting of coins, striking millions of pieces for Britain and other countries, and supplying the Royal Mint with up-to-date equipment.