In this work, the structural, electronic, and optical properties of Fe and Co co-doped CuO (Cu_1−x-yFe_xCo_yO) are studied using the DFT+U approach. The most favorable spin configuration of the doped atoms is found by comparing lattice energies of structures where the dopants are placed in different Cu sites, with different spin orientations relative to each other. It is observed that the band gap decreases from the value of pure CuO after co-doping with Fe and Co. This makes the material suitable for p-type semiconductors. The antiferromagnetic CuO shows strong ferromagnetic ground state after co-doping. The electronic and optical properties are thoroughly studied and found in fair agreement with experimental results found in the literature. It is observed that the conduction band became narrow after the co-doping, which in turn may be responsible for the overall redshift of the optical transitions.