This chapter details the enzymatic conversion of various feedstocks into biodiesel, different immobilization techniques, lipase immobilization, and factors that affect enzymatic conversion. Lipases are extensively employed in various chemical reactions such as hydrolysis, alcoholysis, esterification, and transesterification of carboxylic esters. In irreversible immobilization, enzymes are attached to support material only single time; they cannot be detached without damaging either the enzyme or the support material. Physical adsorption and various non-covalent bonding, such as affinity and chelation binding, are reversible in nature and commonly used for immobilizing enzymes. Immobilized lipase shows many advantages compared to free lipases such as easy recovery and reuse, higher adaptability for continuous operation, less effluent problems, greater pH and thermal stability, and higher tolerance to reactants and products. Lipase-catalyzed transesterification for biodiesel production has gained a lot of attention due to mild reaction conditions, environmental friendliness, and wide adaptability for feedstocks.