The province is known as one of the archipelago's holiest sites in the Pre-Christian native religion. It is here where the God of Hurricanes was persuaded to relent his attacks on the islands by Da, the God of Peace. The province in pre-colonial times was much influenced by the Rajahnate of Butuan which was nestled in present-day Agusan del Norte. It was also used as the entry point of the Rahajnate of Ternate, present-day Moluccas of Indonesia, to attack the Rajahnate of Butuan, Rajahnate of Cebu, the indigenous settlements in the Anda Peninsula of Bohol, and the Kingdom of Dapitan (located 'between' Panglao and Bohol), which later moved in northern Zamboanga after the Kingdom of Dapitan was destroyed.
Although one of the newest provinces of the country, settlements in the Dinagat Islands were already present during the Spanish regime as a result of migration of people from nearby provinces of Bohol and Leyte. The so-called mystical province played an important role in the country's history, particularly during World War II.
The municipality of Dinagat is the oldest community in the province. In the early days, a story was told that a stranger reached the place in search of greener pastures. He approached a native and asked what the inhabitants do for a living. The natives said that they farm and fish to live. The stranger's interest in fishing prompted him to inquire where they fish, and the native replied and pointed to a place saying dinhi niini na dagat (here from this bountiful waters). Since then, the place was called "Dinagat".