Boron-doped 〖Ga〗_(1-x) B_x Se (x = 0.3,0.5 and 1.0%) single crystals were successfully synthesized and their optical properties were investigated using UV–Vis spectroscopy. All samples exhibited a sharp absorption edge around 630-640 nm, indicating dominant band-to-band electronic transitions and preservation of the intrinsic optical characteristics of the GaSe host lattice. The optical band gap values, determined from Tauc analysis assuming a direct allowed transition, showed a slight red shift with increasing boron content, decreasing from 1.963 eV to 1.949 eV. This minor band gap narrowing is attributed to subtle lattice strain and defect-related effects induced by boron incorporation, while the overall band structure remains largely unchanged. Extinction coefficient analysis revealed low optical attenuation in the near-infrared region, with only weak composition-dependent variations related to sub-bandgap absorption. These results demonstrate that low-level boron doping provides an effective approach for fine-tuning the optical properties of GaSe, highlighting the potential of 〖Ga〗_(1-x) B_x Se crystals for optoelectronic and photodetector applications.