Ouinhi is a town, arrondissement, and commune in the Zou Department of south-western Benin. The commune covers an area of 483 square kilometres and as of 2002 had a population of 38,319 people. It is bounded on the north-west by the commune of Zagnanado, south-west by the commune of Zogbodomey, south by the commune of Bonou and east by the commune of Adja-Ouèrè.