Aluminium alloy 6061 (AA6061) is widely used across various industries. It has untapped potential in diverse sectors due to its exceptional strength, lightweight characteristics and corrosion resistance. It finds value in aerospace, automotive, marine, sports gear, architecture, renewable energy, electronics, healthcare devices, packaging and defence. This study investigates the impact of heat treatment on AA6061 on its microstructural and mechanical properties (tensile strength and microhardness). The main goals of this study involve assessing the mechanical properties of AA6061 after subjecting it to solution heat treatment at various temperatures and time intervals. Furthermore, the study aims to understand the relationship between microstructural alterations and mechanical properties in AA6061 following heat treatment. A combination of tensile tests, hardness tests, and scanning electron microscopy (SEM) to examine the material's microstructure. The findings reveal that the sample subjected to the heat treatment of 450°C for 60 minutes exhibited the highest tensile strength, boasting an impressive 130.9 MPa, coupled with a remarkable hardness of 19.8 HRB. Conversely, the sample treated at 550°C for 60 minutes displayed the most significant elongation percentage, reaching a remarkable 46%. These results can be explained by analysing the microstructure. Finer grain boundaries led to increased tensile strength and hardness, while a larger dendritic microstructure was linked with lower tensile strength and hardness. Remarkably, the second one led to higher elongation percentages. Therefore, precise control of the heating temperature and duration is crucial to enhance the performance of aluminium alloy, AA6061. With continuous research, alloy improvement and creative design, AA6061 have the potential to enhance performance and efficiency in these areas, driving technological advancements and better products.