Biodiesel is a long-chain fatty acid ester produced from renewable and biological resources such as used cooking, animal fat, vegetable oil, and algae. Biodiesel is a renewable and clean fuel as it reduces carbon monoxide, carbon dioxide, hydrocarbons, and particulate matter emissions compared with petroleum-based diesel fuel. Production of biodiesel from renewable resources is done through the transesterification reaction at which the organic group (alkyl) of alcohol is substituted with the organic group of a triglyceride– the main component of the feedstock –producing fatty acid alkyl ester (biodiesel) and crude glycerol. Biodiesel can be used in pure form (B100) or may be blended with petroleum diesel at any concentration if its specifications is identical to the international standard specifications provided by American standard for testing materials (ASTM) or EN14214 in the European Union for alternative fuels. Biodiesel can be used as a fuel in many applications such as generators, diesel vehicles, heaters, and boilers. In this paper, the different types of biodiesel feedstocks, feedstocks treatment methods, and biodiesel production technologies are reviewed and summarized.