Nicholas III
Nicholas III may refer to:
- Patriarch Nicholas III of Constantinople, ruled 1084–1111
- Pope Nicholas III, ruled 1277–1280
- Nicholas III, Lord of Mecklenburg
- Nicholas III of Saint Omer
- Nicholas III, Duke of Opava
- Patriarch Nicholas III of Alexandria, ruled 1389–1398
- Prince Karl Emich of Leiningen, pretender to the Russian throne as Nicholas III