James Alexander Lawson Duncan (1899-30 September 1974) was a Scottish army officer and Conservative Party politician who was briefly active in local government in London.
The only child of Alexander Lawson Duncan of Jordanstone, and Margaret nee Dawson. Following education at the University of Cambridge he received a commission in the Scots Guards in 1917 and saw service at the Western Front in the closing stages of the First World War. In 1920 he was released from the army and moved to Northern Rhodesia where he had a large farm.
He inherited his father's estate in 1924 and returned to the United Kingdom. From 1925-28 he was a Municipal Reform Party member of the London County Council representing Finsbury. From 1931 he was member of parliament for Kensington North from 1931-45. During the Second World War he temporarily rejoined the Scots Guards, rising to the rank of captain.
He lost his parliamentary seat at the 1945 general election, but returned to the House of Commons in 1950 as MP for the Scottish constituency of South Angus, holding the seat until 1964.
In the 1957 Birthday Honours he was created Sir James Duncan, Baronet of Jordanstone
Some information here 
Image here 
- London Gazette: . 13 June 1957.