Which Dragon King rules the South Sea?

The Dragon King who rules the South Sea is Ao Qin.

Ao Qin is one of the Dragon Kings of the Four Seas in Chinese mythology and is associated with the South China Sea, sometimes also called the West Philippine Sea in modern geographic usage. As a Dragon King, he belongs to a group of powerful water deities traditionally linked with rain, storms, rivers, oceans, and control of the weather.

The Four Seas correspond to the cardinal directions. Ao Guang rules the East Sea, Ao Run or Ao Jun rules the West Sea, Ao Shun rules the North Sea, and Ao Qin rules the South Sea. These names appear in traditions and classical novels such as Journey to the West and Investiture of the Gods, although variant names and relationships can differ between texts.

The most common confusion is between Ao Qin and Ao Guang. Ao Guang is the Dragon King of the East Sea and is especially prominent in stories about Nezha. Ao Qin is the southern king. “Dragon King” can also mean the generic Dragon God, so the question’s directional wording is important: it points specifically to the Four Seas system.