Onil

For people with the given name, see Onil (given name). thumb|230px|Onil thumb|150px|Onil's flag thumb|150px|Onil's coat of arms

Onil (; ) is a town and municipality located in the comarca of L'Alcoià, in the province of Alicante, Valencian Community, Spain. It has an area of 48.41 km2 and, according to the 2021 census, a total population of 7,612 inhabitants and a population density of 154.22 inhabitants/km2. Onil is located next to the mountain called Serra d'Onil in the Serra de Mariola, 36 km from Alicante city.