Șieu is a commune in Bistrița-Năsăud County, Transylvania, Romania. It is composed of four villages: Ardan (Garendorf; Árdány), Posmuș (Paßbusch; Paszmos), Șieu, and Șoimuș (Almesch; Sajósolymos). The commune is situated on the Transylvanian Plateau, at an altitude of 406 m, on the banks of the river Șieu. It is located in the southern part of Bistrița-Năsăud County, 22 km southeast of the county seat, Bistrița, on the border with Mureș County. Șieu borders the following communes: Cetate to the north, Budacu de Jos to the northwest, Mărișelu to the west, Batoș, Mureș County to the south, and Șieuț to the east. The route of the Via Transilvanica long-distance trail passes through the village of Posmuș. At the 2021 census, Șieu had a population of 2,932; of those, 87.72% were Romanians, 7.37% Roma, and 2.08% Hungarians.