With increasing longevity in many countries, the demand for prostheses to replace damaged hard tissue is growing. In recent years, efforts have focused on developing new titanium (Ti) alloys with a lower Young’s modulus, closer to that of human bone (30 GPa), given the average cost of $32,933 for prosthesis replacement procedures. While such alloys already exist, metastable β-Ti alloys have drawn attention due to their excellent combination of good strength, biocompatibility, and the abundance of titanium in the Earth’s crust. A better understanding of their properties and behavior, such as structure and element interaction, could create more efficient and long-lasting materials. To address this demand, this study aims to develop Ti-15Mo-yNb alloys (13, 15, and 19 at%) through arc melting, heat treatment, forging, and quenching. The alloys were analyzed using XRD, SEM, EDS, and mechanical testing. The β-Ti and α”-Ti phases were found, with Vickers hardness values ranging from 290 HV to 392 HV and Young’s modulus between 66 GPa and 75 GPa. The results show that higher Nb content helps form the α”-Ti phase at grain boundaries and improves the mechanical properties of the β-Ti matrix alloys.