Enzymes, together with the process of self-assembly, constitute necessary components of the foundation of life on the nanometre scale. The exceedingly high efficiency and selectivity exhibited by enzymes for catalyzing biotransformations naturally lead to the exploration of enzyme mimics and the applications of enzymes in industrial biotransformations. While the mimicking of enzymes aims to preserve the essence of enzymes in a simpler system than proteins, industrial biotransformations demand high activity and stability of enzymes. Recent research suggests that small peptide-based nanofibers in the form of molecular hydrogels can provide a general platform to achieve both important goals. This tutorial review will introduce the recent progress of these research activities on small peptide-based nanomaterials for catalysis and hopes to provide a starting point for further explorations that ultimately may lead to practical applications of enzymes and enzyme mimics for addressing important societal problems in energy, environment, and health.