“Sabyinyo” is derived from the Kinyarwanda word “iryinyo”, meaning “tooth”; also “sabinyo, sabino”. This is an extinct volcano in eastern Africa in the Virunga Mountains. It is north-east of Lake Kivu, one of the African great Lakes, and west of Lake Bunyonyi in Uganda. The summit of the mountain is at 3,645 meters (11,959 ft ), marks the intersection of the borders of the Democratic Republic of the Congo (DRC), Rwanda, and Uganda. It also is within the adjoining national parks established by these countries: Virunga national park in the DRC, the volcanoes national park in Rwanda, and Mgahinga gorilla national park in Uganda.

The slopes of Mount. Sabyinyo are a habitat for the critically endangered mountain gorilla. The mountain carries the local nickname “old man’s teeth” because its serrated summit resembles worn teeth in a gum line (in contrast to the perfect conical summits of the adjacent mountains in this range).