He was a grandson of Sir William Henry Walter Montagu Douglas Scott, 6th Duke of Buccleuch & 8th Duke of Queensberry and Lady Louisa Jane Hamilton, and a paternal first cousin to Lady Alice, Duchess of Gloucester, later known as Princess Alice, Duchess of Gloucester.
As was the case with his father, Claud Andrew Montagu Douglas Scott was known most commonly by his middle name, Andrew. He was educated at Eton College, Eton, Berkshire, England. On Saturday 10 August 1929, Montagu Douglas Scott married Lady Victoria Doris Rachel "Doria" Haig (1908-1993), daughter of Field Marshal Douglas Haig, 1st Earl Haig and Dorothy Maud Vivian.
Andrew and Doria had two children together: Captain Douglas Andrew Montagu Douglas Scott (21 June 1930 – 21 June 2010) Henrietta Montagu Douglas Scott (9 December 1934 – 20 February 2008) Andrew and Zalia had one child together: Nicholas Herbert Montagu Douglas Scott (17 November 1954) Claud Andrew Montagu Douglas Scott was promoted to colonel while in the service of the Irish Guards.
He was promoted to brigadier while in the service of the 1st Guards Brigade. Brigadier Scott fought in the Second World War, where he was mentioned in despatches.
Claud Andrew Montagu Douglas Scott died on Sunday 24 January 1971, in his 65th year.
