Alexander William Douglas Reid [also known as A. W. D. Reid, and as Alexander W. D. Reid] was born in c.1884 and studied at Trinity College, Dublin. He subsequently practised an architect. In 1910, with Laurence Aloysius McDonnell (1867?-1925), he formed the Dublin-based architectural partnership, McDonnell & Reid. The partnership was dissolved in 1914 with the outbreak of World War One in 1914 when Reid enlisted in the Durham Light Industry. Following the war Reid settled in England and set up a practice in London.
He was elected a member of the Architectural Association of Ireland (AAI) in 1903 and was Vice-President of the AAI in 1911-13. He was also elected an Associate of the Royal Institute of British Architects (ARIBA) in 1921 and a Fellow of the Royal Institute of British Architects (FRIBA) in 1931. By 1947 he had retired.
His address was given as 9 Hume Street, Dublin in 1910; 20 Ely Place, Dublin in 1911 and 1915; Brown Cottage, Ovalways, Gerrard's Cross, Buckinghamshire in 1923; and 14, Bedford Row, London in 1926; 1 Lincoln's Inn Fields, London in 1939; and Duncombe, Landscore Road, Teignmouth, South Devon in 1954.