Different nano-structured solid materials with well-defined micro-, meso-, and hierarchical porosity and controlled catalytic properties (acid/base, redox) are capable of catalyzing a wide range of chemical reactions (e.g., oxidations, reductions, acid/base processes, etherifications, condensations, etc.) in the liquid and gas phases, interesting for the industrial production of chemicals, fuels, energy and energy vectors. The presence of isolated metallic species, homogeneously distributed in the form of nanoparticles on specific acid/base supports or adequately incorporated in the inorganic framework of well-structured materials, provides multi-functional capacities to afford catalytic transformations and multi-step reactions in “one-pot” or “cascade-type” processes, thus reducing reaction steps and operations costs and making processes more efficient and sustainable. This Special Issue welcomes contributions devoted to the design, characterization, and application of novel nano-structured catalysts for sustainable chemical processes, mainly those focussed on the production of renewable energy and fuels or those related to the transformation of renewable raw materials, such as biomass and its derivatives into valuable products.