Membrane separation processes promise significantly reduced energy requirements compared to classical thermal separation processes. The ability of organic solvent nanofiltration, a pressure-driven membrane process, to operate at mild temperatures makes it especially interesting for oleochemical processes. The membrane cut-off matches the molecular weight of most triglycerides and fatty acids, thus energy-efficient recovery of extraction solvents or selective recovery of fatty acids from waste oils is possible. This chapter presents the potential of organic solvent nanofiltration for important application fields in the oleochemical industry. Furthermore, the processing of non-edible oils and waste oils, which are promising feedstocks for more economic and ecological production processes, is discussed.