Molecularly imprinted polymers (MIPs) have been significantly developed for the specific binding and space mimicking of target molecules in materials. This technique has been applied to biology and chemistry, including sensors, biological receptors, drug delivery, adsorption, and catalysis. Molecularly imprinted catalysts (MICs) are utilized as active materials for catalyzing organic reactions by regulating activity and selectivity. Selective catalysis is a method to design artificial enzymatic systems, containing three-dimensional active sites to perform and control catalytic reactions. MIPs in comparison with biological enzyme systems usually have merits like easy preparation, robustness to physical and chemical stresses, and reusability that can be applied as a promising substitute for biomolecules. The efficiency of catalysis in artificial enzyme research is related to the transition state stability of chemical reactions, reducing the activation energy. This chapter focuses on the key aspects required in the usage of molecularly imprinted polymers as catalysts. Also, the preparation of catalytic active MIPs with transition state analog, substrate, and product molecules as the templates is discussed. In addition, we describe various catalysts containing organic bulk polymers, metal complexes, metal ions, and metal nanoparticles with different applications in organic reactions. Finally, the imprinted catalysts consisting of biopolymers and inorganic polymers as well as surface molecularly imprinted catalysts are presented.