Jaco (also sometimes written as Jako) is an island in the Lesser Sunda Islands. It lies across from the easternmost point of the island of Timor, Kap Cutcha. Its geographical coordinates are 8° 27' S and 127° 20' E. Politically it is part of the district of Lautém, East Timor. It is separated from the mainland by a narrow channel, suitable for passage by small vessels only. It is about 10 square kilometers in area and reaches about 100 meters in altitude.
The island is uninhabited. It is considered holy by the indigenous population and entering the island is forbidden.
It is designated as a "Wild Area." It has beautiful sand beaches. Native birds include the dusky cuckoo-dove (Macropygia magna) and the fawn-breasted whistler, (Pachycephala orpheus). It is also part of the new Nino Konis Santana National Park.