Ouinhi is a town, arrondissement, and commune located in the Zou Department of south-western Benin. The commune spans an area of 483 square kilometres and had a recorded population of 59,381 people as of 2013.
The administrative territory is divided into three arrondissements: Dasso, Ouinhi, and Tohu, which together comprise 28 villages. Geographically, the commune is bounded by Zagnanado to the north-west, Zogbodomey to the south-west, Bonou to the south, and Adja-Ouèrè to the east.