In this study, bismuth oxide–doped strontium phosphate glasses with low Bi2O3 content were prepared using the melt–quench method. Unlike most earlier reports on phosphate glasses containing transition- or rare-earth oxides, this work emphasizes the combined role of SrO and Bi2O3 in tailoring the electricalElectrical response. The electrical and dielectricDielectric propertiesDielectric properties were investigated by impedanceImpedance spectroscopyImpedance spectroscopy, with special attention to equivalent circuitEquivalent circuit modeling using the Cole–Cole approach, which has not been systematically applied to this glass family. The experimental results demonstrate that the electricalElectrical characteristics of these glasses can be effectively represented by a parallel RC circuit, and key parameters such as resistance (Rb), capacitance (Cb), and relaxation time (τ) were extracted. Analysis of the true dielectricDielectric constant (ε′) as a function of frequency and Bi2O3 concentration revealed strong frequency dispersion and a clear reduction in dipole polarization at higher frequencies. These variations reflect the sensitivity of the dielectric response to subtle local structural changes induced by Bi2O3–SrO interactions. Overall, this study provides new insight into the conduction and relaxation mechanisms of phosphate–bismuthate glasses and underscores the potential of low Bi2O3, SrO-modified systems for dielectricDielectric and energy-storage applications.