Dauin, officially the Municipality of Dauin is a 2nd class municipality in the province of Negros Oriental, Philippines. According to the 2020 cens…Dauin, officially the Municipality of Dauin is a 2nd class municipality in the province of Negros Oriental, Philippines. According to the 2020 census, it has a population of 30,018 people. The municipality was created on January 13, 1908, through Executive Order No. 37.