Significant progress is described in the development of cellular solids, specifically functional and multifunctional foams, prepared by bioinspired approaches and consisting of green components. This article covers recent examples mainly developed at the Materials Science Institute of Madrid, ICMM-CSIC, on bionanocomposites and bioinspired materials conformed as foams. These novel hierarchical porous systems bring out a broad range of advanced applications from biomedical purposes to energy generation and storage.