The success of new therapeutic modalities relies on advancements in synthetic chemistry to produce compounds for evaluation throughout the drug discovery process. The use of non‐canonical amino acids (ncAAs) allows the properties of peptide drugs to be modified and optimised beyond the defined characteristics of the 20 proteogenic amino acids. Synthesis of ncAAs can be either through a bespoke chemical synthesis, or directly from the parent compound – using either traditional chemical reagents or using enzymes – to achieve the desired modification. This review will highlight recent advancements in the enzymatic functionalisation of amino acids to produce a variety of ncAAs.