Artist. Born in Campbeltown (Argyll & Bute), he studied first to be a lawyer but soon abandoned this career for painting, training at the Drawing School of the Royal Scottish Academy in Edinburgh, where he settled. He is noted for his oil paintings of broad expanses of moorland, rolling countryside, sea and sand seen under changing skies, with some areas bathed in bright sunlight while other areas are in shadow. His works include Aberlady, East Lothian (c.1906, in Aberdeen Art Gallery), Sunset, Argyllshire (1913, in the Hunterian Art Gallery in Glasgow), Edinburgh from Corstorphine Hill (held by the City of Edinburgh Council), Fishing Boats at Port Righ, Carradale (1898, in Campbeltown Museum), with other works held by the Stewartry Museum in Kirkcudbright and the Smith Art Gallery & Museum in Stirling.
Mitchell was elected a Fellow of the Royal Scottish Academy in 1919. He died in Corstorphine (Edinburgh) and lies buried in the kirkyard of Gogar Parish Church. His son was the engineer Colin Campbell Mitchell (1904-69).