George Angus Mitchell [also known as Angus Mitchell, and as G. Angus Mitchell] was born in Aberdeen, Scotland on 27 November 1896 and was the son of the architect George Bennett Mitchell (1865-1941). He joined his father's practice as an apprentice in 1913, and that year also enrolled at Aberdeen School of Architecture. In December 1915 his studies were interrupted by military service during World War One. Following the war he returned to his father's practice and completed his studies at Aberdeen School of Architecture, receiving his diploma in July 1921. Later that year he was elected an Associate of the Royal Institute of British Architects (ARIBA). In 1929 he became a partner in his father's practice which was renamed George Bennett Mitchell & Son. In 1930 he was elected a Fellow of the Royal Institute of British Architects (FRIBA)
He served again in the Army during World War. With war service over, in June 1945 he returned to his father's practice. Although his father had died in 1941, he retained George Bennett Mitchell & Son as the title of the firm. He was President of the Aberdeen Chapter of the Royal Incorporation of Architects in Scotland in 1939, 1947 and 1949. In 1950 he visited South Africa.
His private address was given as 4 Deemount Terrace The Holt, Aberdeen, Aberdeenshire in 1901 and 1921; 31 Albert Terrace, Aberdeen in 1930 and 1950; and Thornhill, Newburgh, Aberdeenshire, Scotland in 1962 and 1964. His business address was 148 Union Street, Aberdeen, Scotland in 1913 and 1921; 1, West Craibstone Street, Bon Accord Square, Aberdeen, Scotland in 1921 and 1950. He died in Newburgh, Aberdeenshire on 6 December 1964
Shop for Reid & Pearson, St Nicholas Street and Schoolhill, Aberdeen (c.1922); Institute for Royal National Mission for Deep Sea Fishermen, Aberdeen (1925); House for Rev. Herbert Reid, Gourock, Renfrewshire (1929); House and outhouse on St Eunan's Road, Aberdeen (1930); House for Thomas Ayrton, Springfield Avenue, Aberdeen (1930); Houses, Littlewood Estate, Alford, Aberdeen (c.1930); All Saints' Episcopal Church of Scotland and Church Hall, Hilton, Aberdeen (1931-35); Car showroom and offices for Claud Hamilton Ltd (1935-36); Liverpool Insurance Company building, Aberdeen (1936); Manse, Parish Church, Rothienorman, Aberdeenshire (1936); Mausoleum, Littlewood Estate, Alford, Aberdeenshire (1937); National Bank of Scotland, Peterhead branch, Aberdeenshire (1939); Church, Stockethill, Aberdeen (1949-50); and Primary County School, Aboyne, Aberdeenshire (1951)