Heterogeneous catalysis has been around for a long time, but has still much room to grow. The empirical trial-and-error mode used to develop catalysts in early times has progressively made way for a more molecularly driven approach to their design. Modern surface-sensitive techniques have opened the way to a better understanding of the mechanisms of catalytic reactions and the demands imposed on catalytic sites. Computational studies have added insights into the structural and energetic details of surface species and the kinetic driving forces for specific surface reactions. Novel nanotechnology and synthetic advances have provided new methods to manufacture better-defined catalysts, with high concentrations of the active sites identified by fundamental mechanistic studies. All combined, these advances have led to the design of new catalysts by taking advantage of the size and shape of the nanoparticles used as active phases and of specific structures and the nature of the support. New research has also been directed to the development of more sophisticated nanostructures, to add new functionalities to simpler catalysts or to combine two or more primary functions into one single catalyst. Much progress has been made in these directions, but the new tools are yet to be fully exploited to resolve present limitations in a myriad of catalytic systems of industrial importance, for energy production and consumption, environmental remediation, and the synthesis of both commodity and fine chemicals.