Dame Louise Margaret Leila Wemyss Paget, Lady Paget, GBE (born 9 October 1881 – died 24 September 1958) was a British humanitarian, active in the cause of Serbian relief, beginning in World War I.
The daughter of General Sir Arthur Henry Fitzroy Paget (1851–1928) and his wife, Lady Mary Fiske Paget (née Stevens; died 1919), she married her third cousin once removed, Sir Ralph Spencer Paget, son of Sir Augustus Berkeley Paget and Countess Walburga Ehrengarde Helena von Hohenthal, on 28 October 1907; the union was childless.
Ralph Spencer Paget was created Knight Commander of the Order of St Michael and St George (KCMG) in 1909 and Louise encouraged him to accept a transfer to the Balkan Kingdom of Serbia in July 1910. Encouraged by Mabel Grujić, the American wife of the Serbian Undersecretary for Foreign Affairs, Lady Paget helped set up a military hospital in Belgrade during the First Balkan War (1912–13). In 1915 she set up a hospital in Skopje to treat wounded Serbs, but also to help fight the epidemic spreading through Serbia. Lady Paget contracted typhoid fever, but recovered.
Dame Louise Paget was the first recipient of the Medal of Honor of the Federation of Women's Clubs of New York City in 1917; other recipients included humanitarian Evelyn Smalley (1919), activist Carrie Chapman Catt (1922, decoration without the eagle), physicist Marie Curie (1929), Madame Chiang Kai-shek, First Lady of the Republic of China (1939), and Austrian-born pioneer atomic scientist Lisa Meitner (1949).
Louise, Lady Paget was invested as a Dame Grand Cross, Order of the British Empire (GBE) in 1917. She was later decorated with the Grand Cordon, Order of St Sava.
She died on 24 September 1958, aged 76, at Kingston-upon-Thames.