Microalgae have attracted increasing interest due to their composition, which is rich in proteins, lipids, carbohydrates, and pigments, and can be used in several applications. Despite the enormous potential, the harvesting procedure makes the commercialization of microalgal biomass economically unfeasible. This process represents almost 30% of the total cost of microalgal production. Harvesting these microorganisms is a significant challenge because they grow in diluted suspensions and have a small size, negative surface charge, and low density. Centrifugation, gravity sedimentation, flocculation, flotation, and filtration are the standard methods for microalgal harvesting. When a combination of these processes is used, the harvesting procedure involves two steps: thickening and dehydration. There is no standard harvesting method as it varies with the microalgal species and the media composition. Regardless of the method chosen for harvesting, it must not contaminate the biomass or change its quality. Furthermore, it should have a low operation time, a high recovery rate, and the potential for large-scale use. This chapter overviews all the main methods currently used to harvest microalgae. Furthermore, the advantages and limitations of each technique are addressed.