Dame Sibyl Mary Hathaway, DBE (née Collings; 13 January 1884 – 14 July 1974) was Dame of Sark from 1927 until her death. Her 47-year tenure spanned the reigns of four overlords: George V, Edward VIII, George VI and Elizabeth II.
Hathaway was a financially troubled widow with six children when she succeeded her eccentric father, William Frederick Collings, as feudal lord of Sark, one of the small Channel Islands. She immediately set about reinforcing her feudal rights and promoting tourism on the island, which she affectionately called "the last bastion of feudalism". When she remarried in 1929, her second husband, Robert Hathaway, legally became her senior co-ruler, but she kept control of the government.
Hathaway's tenure as dame saw the German occupation of the Channel Islands in the Second World War, during which she refused to evacuate and convinced the islanders to stay as well. Her eldest son and heir apparent, Francis William Beaumont, was killed in 1941, while her husband was deported to a Nazi concentration camp in 1943. Hathaway remains best known for her indomitable conduct during the occupation. After the war, she continued her publicity campaign, strengthening the island's tourism industry.