Olives are one of the main cultivation crops across the Mediterranean region and have been occupying an essential part in the diet of people in addition to their economy and culture for years. Besides food, olive oil has been used in various parts of daily life, such as medicines, fuel source, cosmetics, soap and even religious rituals. Olive oil is known to be highly superior to other oil types due to its health protection characteristics since they contain large amounts of monounsaturated fatty acids and natural antioxidants such as Vitamin A, K, cartenoids and phenols. This book presents topical research in the study of olive oil including innovative co-adjuvants to improve olive oil extraction; the chemical composition of olive oil; pesticide residues in olive oil; and natural antioxidants from olive mill wastes.