Dame Katherine Christie Watt, DBE, RRC, CStJ (31 August 1886 – 1 November 1963) was a British military nurse, nursing administrator and civil servant. Watt served in the Queen Alexandra's Imperial Military Nursing Service during the First World War, and the Princess Mary's Royal Air Force Nursing Service in the inter-war period. She was Matron-in-Chief of the Royal Air Force Nursing Service from 1930 to 1938, and worked at the Ministry of Health during and immediately after the Second World War. As Chief Nursing Officer from 1941 to 1948, she was actively involved in the plans for the new National Health Service (NHS).