Sibolga (formerly sometimes Siboga) is a city and a port located in the natural harbour of Sibolga Bay on the west coast of North Sumatra province, in Indonesia. It is located on the western side of North Sumatra, facing the Indian Ocean and is a transit harbour to the Nias island which was hard hit during the 2004 Indian Ocean Earthquake. The City has an area of 10.77 km2 and had a population of 84,444 at the 2010 Census.