Olive oil is a fat obtained from the fruit of the Olea europaea (olive tree), a traditional tree crop of the Mediterranean region. Whole olives are pressed to produce this distinctive oil. This healthiest oil is rich in monounsaturated fatty acids, and is a major component of the Mediterranean diet from ancient time. Populations from that region have longer life expectancies and lower risks of heart disease, high blood pressure and stroke, compared with North Americans and Northern Europeans.

Monounsaturated fatty acids (MUFAs) are considered a healthy dietary fat, as opposed to saturated fats and trans fats.

The oil is used in cosmetics, medicine, cooking, and soaps, and was also used as a fuel for traditional lamps. Olive oil originally came from the Mediterranean, but today it is used worldwide.

In the diet, olives can be eaten whole or chopped and added to pizzas and other dishes. The oil can be used as a dip for bread, for frying, or as a salad dressing. Some people even consume it by the small glassful for medicinal purposes.