Long before Tandag became what it is today-- the bustling capital town of Surigao del Sur -- it was inhabited by the Manobos and the Mamanwas who lived along the river banks under the leadership of Suba , their Chieftain. Suba was later converted into Christianity by Father Juan de la Encarnacion, a Spanish missionary.

          Tandag City is a fifth class component city and the provincial capital of the province of Surigao del Sur in the island of Mindanao. According to the 2015 census, it has a population of 56,364 people. It has a national secondary airport and a seaport.

          The city celebrates the "Diwatahan Festival" on the third week of January in honor of Señor Sto. Niño. It also commemorates "Araw ng Tandag" every September 10 showcasing the city's blissful achievements through the years.

          Farming and fishing are the main economic activity for most of the people in Tandag. Chief farm products are rice, corn, and coconut. Livestock and poultry raising are also important sources of income.