Sheep milk contains much higher concentrations of protein, fats, minerals, and vitamins than milk from other common domestic species such as cows and goats. High nutritional value and lower allergic sensitization compared to cow milk make sheep milk an ideal source of nutrition for humans. Moreover, advantages in physicochemical characteristics also make sheep milk a very good raw material for processing, especially in cheese making. However, dairy sheep industry remains small in many regions of the world,  mostly due to restricted genetics and limited milk production. Milk yield and composition are influenced by various factors including genetic parameters, dietary nutrient composition, parity, lambing season, milking frequency, and stage of lactation. Future research on dairy sheep in different production systems especially in developing countries and new genes regulating milk production and quality need to be undertaken.