This study investigates the modification of bamboo fibre in affecting the physical, mechanical, and adhesion properties of stone mastic asphalt mixtures. Climate change and heavy traffic have increased the deterioration of the pavement, high maintenance costs, and several other performance-related problems. Hence, this study focused on investigating the physical and mechanical properties, evaluating the microstructure condition, and validating the adhesion performance of modified and unmodified stone mastic asphalt (SMA) mixtures. Different tests such as Marshall Stability, Cantabro Abrasion, Contact Angle, and Scanning Electron Microscopy (SEM) tests were performed using bamboo fibre at 0, 0.5, 1.0, and 1.5%. The highest stability was 10.876 kN and stiffness 3.15 kN/mm at 1.5% of bamboo fibre, and the reduction in Cantabro loss was 2.6%, with a lower contact angle of 97.92°, which reflects that there is an increase in adhesion and resistance to deformation. It can be concluded that adding a significant amount of bamboo fibre will enhance the durability, strength, and adhesion properties of SMA, therefore offering a very promising solution for sustainable and durable asphalt pavements.