One-dimensional rutile TiO₂ is an important inorganic compound with applicability in sensors, solar cells, and Li-based batteries. However, conventional synthesis methods for TiO₂ nanowires are complicated and entail risks of environmental contamination. In this work, we report the growth of TiO₂ nanowires on a Ti alloy powder (Ti-6wt%Al-4wt%V, Ti64) using simple thermal oxidation under a limited supply of O₂. The optimum condition for TiO₂ nanowire synthesis is studied for variables including temperature, time, and pressure. TiO₂ nanowires of ~5 μm in length and 100 nm in thickness are richly synthesized under the optimum condition with single-crystalline rutile phases. The formation of TiO₂ nanowires is greatly influenced by synthesis temperature and pressure. The synthesized TiO₂ nanowires are characterized using field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), and high-resolution transmission electron microscopy (HR-TEM).