Microalgae are considered promising raw materials for the sustainable production of biofuels, as they offer advantages over traditional agricultural crops, such as higher productivity, use of wastewater or brackish water, high CO2 capture capacity, and potential for the generation of various biofuels, such as biodiesel, bioethanol, biogas, biohydrogen, etc. However, microalgae productivity depends on many operational parameters of the bioreactors, including light intensity, temperature, pH, nutrients, gas transfer, choice of algal strain, etc., indicating the need for customized bioreactor designs. Thus, this chapter presents a summary of the main parameters that impact microalgae productivity and biofuel production in bioreactors.