Douglas was educated at Glasgow University and later became a partner in Douglas & Company, solicitors, and also worked as a journalist. A member of Battersea Borough Council, he was mayor of Battersea in 1922–1923.
Having unsuccessfully fought Yeovil in 1929, he was elected as the Member of Parliament (MP) for Battersea North at a by-election in 1940, a seat he held until 1946, and served as Parliamentary Private Secretary to the Parliamentary Secretary to the Board of Education from 1940 to 1945 and to the Home Secretary from 1945 to 1946 (James Chuter Ede held both positions).
After the CommonsEdit
In 1946 Douglas he resigned from the House of Commons on being appointed Governor of Malta, which he remained until 1949. Douglas was made a KCMG in 1947 and in 1950 he was raised to the peerage as Baron Douglas of Barloch, of Maxfield in the County of Sussex. He was also a member of the Public Works Loan Board from 1936 to 1946 and of the Railway Assessment Committee from 1938 to 1946 and served as Chairman of the Finance Committee of the London County Council from 1940 to 1946. After being raised to the peerage he was a Deputy Speaker of the House of Lords.
Lord Douglas of Barloch died in March 1980, aged 90. The title became extinct on his death.