Background
Welsh was born in Bedford, Eastern Cape to Alexander Robert Welsh, a Presbyterian clergyman from Scotland, and Bertha Solomon, the first woman barrister in South Africa and the first woman member of the South African Parliament. In 1901, Welsh married Maude Marianne Smit, daughter of New Hampshire (U.S.)
Education
He was educated at Dale College in King William"s Town.
Career
He was Speaker of the Southern Rhodesian Legislative Assembly from 1935–1952. He passed his final law exams in 1896 and was admitted to the Cape Supreme Court as an attorney and notary. Smit Justice of the Peace of Seymour, Cape Province, and had three daughters.
Two years later he joined the firm of Frames and Grimmer in Bulawayo as managing clerk.
Charles Coghlan arrived in Bulawayo in 1900 and the firm became Frames and Coghlan. However, in 1902 Frames left for Johannesburg and dissolved the partnership with Coghlan.
Welsh became a partner of the firm on 1 January 1903 and they practised as Coghlan and Welsh. Welsh was elected in 1927 to the Southern Rhodesian Legislative Assembly as the member for Bulawayo North, replacing Sir Charles Coghlan, who had died in office, and was re-elected several times until 1935.
He succeeded Lionel Cripps as Speaker of the Assembly in 1935 and served until 1952.
Welsh was a director of Rhodesia Sugar Refinery, Limited and of Knitting and Clothing Factory. Sir Allan Ross Welsh died in Bulawayo aged 82. He was photographed by the Bassano studio in London in 1937 and the prints reside with the National Portrait Gallery, London.
Membership
Cripps was not a member of the House and Welsh did not contest any further elections after 1935.