Sadu (; ) is a commune in Sibiu County, Transylvania, Romania, at the foothills of the Cindrel Mountains, 27 km south of the county capital Sibiu, in the Mărginimea Sibiului ethnographic area. It is composed of a single village, Sadu.
In 1910 the village had 2,143 inhabitants.
The Sadu is a left tributary of the river Jiu in Romania. It discharges into the Jiu in Bumbești-Jiu.
The Sadu is a right tributary of the river Cibin in Romania. It discharges into the Cibin in Tălmaciu. The Negovanu and Sadu II dams are located on the Sadu.
Sadu may refer to:
- Sadu, commune in Romania
- Sadu (Jiu), a river in Romania, tributary of the Jiu
- Sadu (Cibin), a river in Romania, tributary of the Cibin
- Kalateh-ye Sadu village in Iran
- Sadu language from China
- Sadashiv Shinde, known as "Sadu", an Indian cricketer
- Al Sadu, or Sadu, an embroidery form in geometrical shapes hand-woven by Bedouin people
- Sadu House in Kuwait, a museum of bedouin Sadu weaving, established by the Al Sadu society
- Sadu-Hem, one of the Ogdru Hem fictional creatures in the Hellboy universe
- Sadu Zai descendants of the Abakhel (Pashtun tribe)
- Ramkali Sadu, a Sikh composition