The introduction of certain nutraceutical raw materials and extracts and single-cell proteins as yeast or microalgae complete the image of an all-in-one tablet for a healthier lifestyle. The huge potential of microalgae to tolerate high CO2 concentration and produce oil approximately 60% offers valuable, sustainable and renewable fuel resource yet to be tapped economically. This chapter focuses on the potential utility of algae as space food for space missions and habitation. Microalgae, such as Arthrospiraplatensis, can provide proteins, amino acids, minerals, vitamins and so on and meet human beings' nutritional needs; in addition to that, microalgae can be easily cultivated when compared to plants. Two types of microalgae and cyanobacteria are suitable candidates for life support systems. Because of its amino acid, vitamin and lipid content, the microalgae Chlorella vulgaris is a great candidate for a space food for humans.