Sir Daniel Grian Alexander is a former politician who was Chief Secretary to the Treasury between 2010 and 2015. He was the Member of Parliament (MP) for the Inverness, Nairn, Badenoch & Strathspey constituency from 2005 until the general election in May 2015. In his first parliamentary term (2005–2010), Alexander was the Liberal Democrat spokesperson for Work and Pensions (2007–2008), the Chief of Staff to party leader Nick Clegg, and Chair of the Liberal Democrat Manifesto Group (2007–2010).

The Chief Secretary to the Treasury is a ministerial office in the government of the United Kingdom and is the second most senior ministerial office in HM Treasury, after the Chancellor of the Exchequer. The office was created in 1961 to share the burden of representing HM Treasury with the chancellor.