Elsie Knocker (July 29, 1884 – April 26, 1978) was a British nurse and ambulance driver in World War I who, together with her friend Mairi Chisholm, won numerous medals for bravery and for saving the lives of thousands of soldiers on the Western Front in Belgium. Dubbed "The Madonnas of Pervyse" by the press, the two became the most photographed women of the war.