Nowadays, biofuel production of new raw materials has gained renewed interest. For that reason, the objective of this work is to use marine macroalgae for biodiesel and biomass production. The obtained results show that macroalgae are a suitable energy source for biodiesel production by direct transesterification, avoiding the previous step of oil extraction. It is an effective process because 95% of the oil is extracted. To analyze the optimum reaction conditions, the reaction was carried out at different amounts of methanol, catalyst concentrations, reaction temperatures, and reaction times. In addition, the macroalgae residue after transesterification was analyzed and it is suitable as fuel in biomass boilers.