Siyadebrina Wayu is one of the woredas in the Amhara Region of Ethiopia. Located in the Semien Shewa Zone, Siyadebrina Wayu is bordered on the south by the Oromia Region, on the west by Ensaro, on the north by Moretna Jiru, and on the east by Basona Werana. Towns in this woreda include Deneba. Siyadebrina Wayu was part of the former Siyadebrina Wayu Ensaro woreda.
Based on the 2007 national census conducted by the Central Statistical Agency of Ethiopia (CSA), this woreda has a total population of 61,046, of whom 31,322 are men and 29,724 women; 4,522 or 7.41% are urban inhabitants. The majority of the inhabitants practiced Ethiopian Orthodox Christianity, with 99.58% reporting that as their religion.