Brigadier James Roderick Sinclair, 19th Earl of Caithness CBE, DSO, GH (29 September 1906 – 1965) was a distinguished British Army officer during World War II and was also chief of Clan Sinclair.He joined the Gordon Highlanders (now amalgamated with the Highlanders (Seaforth, Gordons and Camerons)) and rose to the rank of Brigadier and as such led his regiment (part of the 51st Highland Division) through France, Belgium, the Netherlands into Germany during World War II and was decorated with the Distinguished Service Order and made Commander of the Order of the British Empire.In 1949 he was appointed the first Commander of the Ceylon Army and played a major role in establishing it as a regular army from the volunteer Ceylon Defence Force till 1952.