LiI–AgI–B₂O₃ glasses doped with different concentrations of MnO (ranging from 0 to 0.8 mol%) were prepared. Electrical and dielectric properties have been studied over a wide frequency range of 10⁻² – 10⁶Hz and in the temperature range from 173 to 523 K. The valence states of manganese ions and their coordination in the glass network have been investigated using optical absorption, luminescence, and ESR spectroscopy. The analysis of the spectroscopic results has indicated that the manganese ions exist in both Mn²⁺ and Mn³⁺ states and occupy octahedral and tetrahedral positions. With increasing MnO concentration there is a gradual increase in the tetrahedral occupancy of Mn²⁺ ions at the expense of octahedral occupancy in the glass network. The results of dc conductivity have indicated that when T > θ_D/2, the small polaron hopping model is appropriate and the conduction is adiabatic in the nature. Further, the analysis of experimental data indicates that there is a mixed, ionic and electronic, conduction. It has been observed that the electrical conductivity decreases as the concentration of MnO increases suggesting the electronic conduction controlled by polaron hopping between manganese ions. In the low temperature region, up to 250 K, the ac conductivity is nearly temperature independent and varies linearly with frequency, which can be explained by the quantum mechanical tunneling (QMT) model. The dielectric properties have been analyzed in the framework of complex dielectric permittivity and complex electrical modulus formalisms. The evolution of the complex permittivity as a function of frequency and temperature has been investigated.