While many engineering cellular solids or foams are based on metallic and polymeric materials, ceramic foams are often used for non-structural applications. The main limitation of using ceramic foams as structural components are their brittleness and flaw sensitivity. In this talk, I will present our recent works in elucidating the structural design principles of natural ceramic or biomineralized cellular solids from a variety of model systems, such as echinoderm stereom, cuttlefish bone, and sponges. These structures are characterized by their highly mineralized porous morphology, yet exhibiting remarkable damage tolerance, in stark contrast to synthetic ceramic foams. We utilize a combinatorial approach by integrating quantitative 3D structural analysis, 4D mechanical analysis, theoretical and mechanical modeling to establish the structure-property relationship for these biological materials. The structural design strategies to overcome the intrinsic brittleness of porous ceramics learned from these biological material systems could inspire novel lightweight ceramic cellular solids.