Bulk hardness and tensile properties of an AA6063 Al-Mg-Si alloy specimens subjected to artificial age-hardening treatment over a wide range of temperatures (373-523 K) and time durations (5 min to 60 days) have been determined and analyzed to predict complete aging kinetics and yield strength. The predictions have been made using simplified hardness-based models. The experimental results are used to generate kinetic models for under- and overaging regimes following the Johnson–Mehl–Avarami and the Lifshitz–Slyozov–Wagner equations, respectively. The obtained kinetic parameters are found to satisfactorily describe the overall aging kinetics of the Al-Mg-Si alloy. Additionally, relationship between the estimated hardness and the yield strength values of the AA6063 alloy has been established and its utility has been validated. The developed hardness-based models can be used as convenient tool to determine the state of aging and to predict the yield strength of Al-Mg-Si alloy.