Type 2 diabetes mellitus is a metabolic disease characterized by high blood sugar levels. Traditionally, amino acids are primarily viewed as the basic building blocks for proteins and peptide synthesis. However, in recent years, amino acids have gained increased attention as signaling molecules that play crucial roles in the maintenance and regulation of metabolic homeostasis. It has been found that there is a close correlation between the metabolism of branched-chain and/or aromatic amino acids and the occurrence or development of type 2 diabetes mellitus. Furthermore, there have been successive reports on the regulation mechanism involved. This article will focus on the metabolic processes, mechanisms and clinical value of branched-chain and aromatic amino acids in type 2 diabetes mellitus. It will also summarize and provide an outlook on the current state of amino acid metabolism in the treatment of diabetes mellitus, with the aim of offering new ideas for the treatment of type 2 diabetes mellitus.