Davao de Oro Foundation Day in the Philippines Date in the current year: March 8, 2024

Davao de Oro is a province in the Davao Region on the island of Mindanao. The history of the region can be traced back to ancient times, when various indigenous tribes began to settle in the Davao Gulf area. The name Davao is believed to be a mixture of similar sounding names that several aboriginal tribes gave to the Davao River: Davohoho, Davohaha, and Duhwow.

In the Late Middle Ages and early modern period, the Davao Region was part of the Sultanate of Maguindanao. Europeans (the Portuguese and the Spanish) first came in contact with the locals in the 16th century. They did not try to colonize the region and let the local tribes live in peace. Maguindanao also maintained friendly relations with British and Dutch traders.

The Spanish colonization of the Davao Gulf region began in the mid-19th century; it was ordered by Governor-General of the Philippines Narciso Clavería y Zaldúa. Datu Bago, the ruler of Davao, led the resistance of the Moro people against the Spanish Empire, but eventually the Spaniards took control over the region.

The Spanish rule in the Philippines ended in 1898. Following the defeat of the Philippines in the Philippine-American War, the Philippines became an unincorporated territory of the United States. The American administration began to improve the infrastructure in the Davao Region and opened the Port of Davao. In 1903, the region became part of the newly established Moro Province. In 1914, the province was replaced by the Department of Mindanao and Sulu, which included the province of Davao. The department was dissolved in 1920, and Davao became an independent province.

For the first two decades of Philippine independence, Davao was one of the largest provinces in the country, with Davao City serving as its capital. However, President Ferdinand E. Marcos split it into three provinces in 1967 as part of governance reorganization in the country: Davao del Sur, Daval del Norte, and Davao Oriental. The territory of what is now Davao de Oro was part of Davao del Norte.

The movement to create a new province by dividing Davao del Norte into two began in the 1980s, but it took more than a decade to actually pass the corresponding bill. The new province, named Compostela Valley, was officially created on March 7, 1998. The anniversary of its founding is a special non-working (previously working) holiday in the province.

In December 2019, a plebiscite was held to determine whether the residents of the province wanted it to have a new name. The main reasons for renaming were to highlight its ties to other provinces in the Davao region and to avoid confusion with the municipality of Compostela in Cebu and Cagayan Valley in Luzon. 97% of the voters supported the renaming of Compostela Valley to Davao de Oro, and the province was officially renamed on December 7, 2019.