The area of catalysis has advanced to the point where the subtle relationships between structure and activity are being investigated in ever increasing detail. As this new age of “Designer Catalysts” advances to higher levels, the need for well defined foundations on which to build catalysts becomes stronger. Clay minerals possess great potential as “Molecular Building Blocks” in the design and synthesis of new catalytic systems. Covered here are various aspects of clay structure, interlayer space, ion exchange, surface modification and delamination that have already found use in the design of catalysts or material that can be used in the area of catalysis. Based on this overview of clay minerals, it is clear that they will play an increasingly important role in the design of new catalysts in the future.