John Duncan Vaughan Campbell, 5th Earl Cawdor, TD (17 May 1900 – 1970), styled Viscount Emlyn between 1911 and 1914, was a Scots-Welsh nobleman. Campbell was the son of Hugh Campbell, 4th Earl Cawdor and Joan Emily Mary Thynne. He fought in the First World War, with the Royal Navy and was awarded the Territorial Decoration. He fought in the Second World War as a Lieutenant-Colonel and was mentioned in despatches. He was invested as a Fellow, Royal Geographical Society, the Society of Antiquaries of Scotland and the Society of Antiquaries.