Nicholas III

Nicholas III may refer to:


 * Patriarch Nicholas III of Constantinople (died 1111), ruled 1084–1111
 * Pope Nicholas III (c. 1225–1280), ruled 1277–1280
 * Nicholas III, Lord of Mecklenburg (after 1230–1289 or 1290)
 * Nicholas III of Saint Omer (died 1314)
 * Nicholas III, Duke of Opava (c. 1339–1394)
 * Patriarch Nicholas III of Alexandria, ruled 1389–1398
 * Prince Karl Emich of Leiningen (born 1952), pretender to the Russian throne as Nicholas III