Stefan Nemanja (Old Church Slavonic: Стѣфань, Serbian: Стефан Немања, pronounced [stefan nemaɲa]  ; ca 1113 – 13 February 1199) was the Grand Prince (Veliki Župan) of the Serbian Grand Principality (Rascia) from 1166 to 1196, an heir of the Vukanović dynasty that marked the beginning of a greater Serbian realm (he is the founding father of the Nemanjić dynasty).

He is remembered for his contributions to Serbian culture and history, being the founder of the powerful Serbian state that would evolve into the Serbian Empire, and the national church. He was the father of Stefan Nemanjić, the first King of Serbia, and of Saint Sava, the first archbishop of the Serbian Orthodox Church. In 1196, he abdicated in favour of his son Stefan, and went to Mount Athos, where he became a monk and took the name of Simeon. Together with his son Sava, Simeon built the Hilandar Monastery in 1198-1199, which became the cradle of the Serbian Church.

After his death, Stefan Nemanja was canonized by the Serbian Orthodox Church under the name Saint Simeon the Myrrh-streaming (Свети Симеон Мироточиви) after numerous alleged miracles following his death. He is regarded the most remarkable Serb for his literary contributions and altruistic attributes, according to the Serbian Academy of Sciences and Arts.