Duncan is a native of Portnahaven, Islay, who has a strong commitment to the West Highlands, the Hebrides and Scottish culture.
He has served on various groups and committees including Skye and Lochalsh Enterprise Company and has a well documented commitment to the development of the UHI network and education in the West Highland area, in particular.
Having graduated in Classics (Latin) and Mediaeval History at Glasgow University he entered the teaching profession and, after posts in Albert Secondary (Glasgow), Lochgilphead High School as head of Classics, Tobermory High School as depute headteacher, he was twenty-one years in Highland Council as Rector of Plockton High School (1992-2013), including establishing the National Centre of Excellence in Traditional Music. He completed a Master of Education (by vacation mode/distance learning) in 1991.
He has been actively involved in Gaelic developments locally and nationally including being the first chairman of Bord na Gaidlig and chaired the BBC Gaelic Advisory Committee.