The effect of Mo-dopant on the structural, electronic, optical and electrical properties of ZnO have been investigated via both first principles study and Boltzmann equations. Results show that, the incorporations of Mo-dopant on Zn-site lead to a blue-shift in the optical gap energy. Furthermore, these incorporations create shallow donor states partially filled around Fermi level in the bottom of the conduction band. Hence, the transmittance is decreased in the visible-IR, whereas, is significantly improved in the UV region. More importantly, the electrical conductivity is fairly enhanced even at high Mo-concentration. Finally, this study reveals to potential to use of Mo-doped ZnO system as n-type transparent conducting electrode.