Gallium oxide (Ga2O3) is a wide-bandgap semiconductor with various applications including power electronics, photodetectors, and solar cells. While n-type conductivity in Gallium oxide (Ga2O3) is commonly observed, achieving stable p-type conductivity remains a significant challenge. Extensive research has been conducted to enhance p-type conductivity in Gallium oxide (Ga2O3), particularly in the monoclinic β-Ga2O3 phase using doping elements such as Ca, Zn, and Cu. In this study, we investigate Cu-doped α-Ga2O3 using first-principles calculations. The CASTEP calculation process was employed for Geometry optimization, utilizing the Perdew-Burke-Ernzerhof (PBE) functional under the Generalized Gradient Approximation (GGA) framework. Our analysis focuses on determining the band structure, density of states (DOS), and optical properties of Cu-doped α-Ga2O3. All simulations were conducted using Materials Studio, a specialized software for material modeling and simulation. Through this research, we aim to uncover the underlying mechanisms of p-type conductivity in α-Ga2O3. We are optimistic that our findings will provide theoretical insights for designing new α-Ga2O3-based semiconductor devices