Although there are various valorisation routes for seaweeds, the preferential use is for food, cosmetic, and pharmaceutical areas, considering the amounts (e.g. scalable by cultivation), nutritional profile, and presence of bioactive compounds. Given the characteristics of seaweeds, the primary recovery methods to be developed should be combined with the obtainment of value-added goods (e.g. pigments for developing bioplastics). Seaweeds can thus be used to directly acquire such molecules of interest, and the biomass can then be transformed into energy or bioproducts. The biorefinery idea takes a multi-solution strategy, obtaining low-volume, high-value-added goods and vice versa, completing the cycle. The cascade valorisation method is used in the biorefinery idea. In this chapter, we focus on the seaweed biorefinery concept from an eco-sustainable and circular economy point of view for a Scale-up to the industrial level, focusing on the benefits and constraints.