Hyperglycemia, characterized by elevated blood glucose levels, is a major risk factor for diabetes mellitus and its complications. While conventional therapies are effective, they are often associated with side effects and high costs, necessitating alternative strategies. This study evaluates the potential of caffeic acid (CA), a phenolic compound with reported antihyperglycemic properties, using both in silico and in vivo approaches. Molecular docking simulations revealed that CA demonstrates a strong binding affinity to protein tyrosine phosphatase 1B (PTP1B), a critical enzyme in glucose metabolism, with superior interaction profiles compared to the reference drug, ertiprotafib. In the in vivo studies, a Drosophila melanogaster model was used to investigate the effects of CA under hyperglycemic conditions induced by a high-sugar diet. Treatment with CA, particularly at a concentration of 500 μM, significantly reduced hemolymph glucose levels and improved several physiological and behavioral parameters, including survival rates, body size, body weight, and larval movement. Furthermore, gene expression analysis demonstrated that CA modulates key metabolic and stress-related pathways, enhancing glucose homeostasis and reducing metabolic stress. These findings highlight the dual utility of in silico and in vivo methodologies in elucidating the antihyperglycemic potential of CA. The results support the development of CA as a cost-effective and ethically viable therapeutic candidate with implications for diabetes management in resource-limited settings.