He has been a Member of the Scottish Parliament (MSP) since 1999, first for the South of Scotland region between 1999 and 2003, and since 2003 for the Galloway and Upper Nithsdale constituency. Prior to his election as Presiding Officer he sat as a member of the Scottish Conservative Party; a position he has resumed since the 2011 election.
Born in Leswalt, in rural Wigtownshire, he was educated at Eton College from 1962 to 1966. He spent two years in New Zealand after leaving school, mainly involved in agricultural work and returned to complete an ONDA in Agriculture at the Scottish Agricultural College at Auchincruive before taking over the family farm in 1971, in the South Ayrshire village of Barr, after a short spell as a Farm Management Consultant.
He ran this hill farm, rearing cattle and sheep, until his election to the Scottish Parliament in 1999. Until the advent of the Parliament, Fergusson says he was not involved in politics to any great extent.
Fergusson is a male-line grandson of Sir Charles Fergusson, 7th Baronet and so is in the remainder to that baronetcy. He is also descended from many Scottish noble families including the Earls of Glasgow, Earls of Dalhousie, and Barons Crofton
Fergusson began holding office as a Community Councillor. He was elected as a member for the South of Scotland region of the Scottish Parliament 1999, and has been Member of the Scottish Parliament for Galloway and Upper Nithsdale since 2003.
He says he entered politics mainly to champion rural causes in his own region: "I was particularly exercised by the fact that whenever anybody talked about rural Scotland, they seemed to talk about the Highlands and Islands. I come from the south of Scotland, and I was keen to provide a rural voice from the south of Scotland."
During this time, Fergusson was lead spokesman for Agriculture and Forestry for the Conservative party, and Convener of the Rural Development Committee, including during the passage of the Protection of Wild Mammals (Scotland) Act 2002. As spokesman, he described laws banning entirely the docking of dogs' tails as "complete and utter folly", arguing that there was a significant difference between the cosmetic docking of entire tails and the shortening of the tails of working dogs. He gained a reputation as a passionate advocate on rural affairs, respected across parties for his political astuteness. He was also one of the biggest rebels from the Conservative whip in the second session of Parliament.
After retaining his marginal seat at the 2007 election, with an increased majority of 3,333, on 14 May 2007 he was elected by his fellow MSPs to succeed George Reid as Presiding Officer by a large majority, beating the other candidate Margo MacDonald by 108 votes to 20.
Because the position of Presiding Officer is an impartial one, the officeholder is required to remove himself from all party politics. Consequently, Fergusson resigned from the Conservative party. He indicated his intention to resign as Presiding Officer at the conclusion of his term, and stand for the Conservative party in 2011. On his return to the Parliament after the 2011 Election, Fergusson stepped down as Presiding Officer and returned to the Conservative benches.
Fergusson announced in 2015 that he would not be seeking re-election in 2016 and would retire from politics after serving as MSP for 17 years. He was succeeded by Finlay Carson at the 2016 election.
Fergusson was knighted in the 2016 Birthday Honours for services to politics, the Scottish parliamentary process and public life in Scotland.
As Presiding Officer, he chaired the Scottish Parliamentary Corporate Body, which has similar functions to that of the House of Commons Commission, and the Parliamentary Bureau, which sets the daily business in the chamber and timetable for progress of bills, subject to approval by the Parliament.
During the draw for the 2007–08 CIS Cup semi-finals, Fergusson mixed up the numbers and miscalled the teams, a mistake that was rectified later that day.
Fergusson is the Honorary President of English-Speaking Union Scotland. He is a member and former President of the Blackface Sheepbreeders Association, and a member of the Scottish Landowners Federation and the Game Conservancy Trust. He lists rugby, curling, Scottish country dancing, folk music and public speaking amongst his hobbies.