Alasdair Roderick Mackenzie (3 August 1903 – 8 November 1970) was a Scottish farmer and politician who became a Liberal Member of Parliament. Mackenzie was a native of Fearn in Ross-shire, a Gaelic speaker, and went to Broadford Junior Secondary School on the Isle of Skye. He became a farmer, and was active in the National Farmers Union, being President of the East Ross branch for two years. He was elected to Ross-shire County Council in 1935 on which he served for twenty years; on leaving the council he was a member of the Crofters' Commission for five years.