British prime minister David Cameron conducted the first major reshuffle of his coalition government on 4 September 2012. The reshuffle, nearly two and a half years after the government was sworn in, was highly anticipated, and eschewed the trend of annual reshuffles which had become common under the governments of the 1990s and 2000s. As a result, many ministers had been in place not just since the government was elected in 2010, but had covered the portfolio in Cameron's shadow cabinet or even earlier; Andrew Lansley had covered the health brief since 2004, when Michael Howard led the Conservatives in opposition.

The Cameron–Clegg coalition was formed by David Cameron and Nick Clegg when Cameron was invited by Queen Elizabeth II to form a government, following the resignation of Prime Minister Gordon Brown on 11 May 2010, after the general election on 6 May. It was the UK's first coalition government since the Churchill caretaker ministry in 1945.