The Inda Sillasie is a river of northern Ethiopia. It originates at the confluence of May Zegzeg and May Be'ati Rivers in the mountains of Dogu’a Tembien, and flows southward to Giba River which empties finally in the Tekezé River. Along its couse, it first takes the name Rubaksa River, then Dabba Hadera River, and finally Inda Sillasie River.

The May Zegzeg is a river of the Nile basin. Rising in the mountains of Dogu’a Tembien in northern Ethiopia, it flows southward to empty finally in the Giba and Tekezé River.