This work demonstrated feasible processes for producing biodiesel from wet biomass of Chlamydomonas sp. JSC4 following the microwave disruption, wet oil extraction, transesterification, and direct transesterification steps. The pretreatment process transformed wet microalgae into more concentrated microalgae cake, allowing large scale operation of microalgae oil extraction. The transesterification of the extracted microalgae oil in hexane was very efficient at a low reaction temperature of 45 °C with simultaneous removal of the unwanted chlorophyll content. Furthermore, direct transesterification of the pretreated microalgae cake for biodiesel production was successful and showed high potential for practical applications.