Sir Alexander Charles Onslow Fergusson (8 April 1949 – 31 July 2018) was a Scottish politician, member of the Scottish Conservatives and Scottish Parliament from 1999 to 2016.
He served as the third Presiding Officer of the Scottish Parliament from 2007 until 2011.
He first became a Member of the Scottish Parliament (MSP) in 1999, initially for the South of Scotland region, and then the Galloway and Upper Nithsdale constituency from 2003 to 2016.
Either side of his term as Presiding Officer, he sat as a member of the Scottish Conservatives.