Tandag, officially the City of Tandag and often referred to as Tandag City, is a fifth class city and the provincial capital of the province of Surigao del Sur, Philippines, on the island of Mindanao. According to the 2010 census, it has a population of 52,114 people.
The city celebrates the "Diwatahan Festival" on the third week of January in honor of Señor Sto. Niño. It also celebrates "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. Tandag has a national secondary airport and a seaport.
Tandag City is located along the northeastern coast of Mindanao Island facing the Philippine Sea. It is bounded on the north by the municipalities of Cortes and Lanuza, on the east by the Philippine Sea, on the south by the towns of Tago and San Miguel, and on the west by the province of Agusan del Sur. It is located 448 nautical miles from Manila and 150 nautical miles from Cebu. The distance from Surigao City in the north to Tandag is about 200 kilometres (120 mi) and 331 kilometres (206 mi) is the distance from Davao City to the south.