Indonesia is a country at the southeastern edge of the Eurasia Continent that has geologically complex conditions. Located at the meeting point of the world plates, this country lies in a zone of high tectonic activity. As a consequence, it is highly vulnerable to natural hazards, such as earthquakes and tsunamis. For instance, Ternate Island in the east of Indonesia is prone to tsunamis. This study intends to map tsunami susceptibility in the coastal areas of Ternate Island. The mapping stages were as follows: weighting and scoring of each parameter and, then, data processing based on Geographic Information System (GIS) using the overlay features in ArcGIS software. The results identified a higher susceptibility to tsunamis in the southern coastal area than the southwestern one. Several influencing factors of tsunami susceptibility on the island are elevation, slope gradient, and coastal material roughness.