Sandao, also known as Sanyu or Sanshu, was a collection of prehispanic Philippine polities recorded in Chinese annals. The name translates to "Three Islands" or "Three Islets." These entities occupied the islands of Jiāmáyán (present-day Calamian), Bālǎoyǒu (present-day Palawan), and Púlǐhuàn, which is possibly located near present-day Manila.
According to the Chinese Gazetteer Zhūfān zhì (1225), Sandao was described as a group of tributary states. They were subordinate to the more powerful nation of Ma-i, which was centered in the nearby island of Mindoro.