Synthesis and ion transport property studies on hot-pressed Na+ ion conducting solid polymer electrolytes (SPEs): (1-x) PEO: x NaPO3, where x in wt.%, are reported. The compositional dependent conductivity (σ) studies revealed SPE film: (75PEO: 25NaPO3) as the optimum conducting composition (OCC) with room temperature conductivity σ ~ 6.7 × 10-7 S cm-1, which is more than two orders of magnitude higher than that of pure PEO polymer host (σ ~ 3.2 × 10-9 S cm-1). Materials characterization and polymer-salt complexation were done with the help of XRD, FTIR, SEM, DSC techniques. In order to understand the ion transport behaviour in SPEs, the measurement on some basic ionic parameters viz. ionic conductivity (σ), ionic mobility (μ), mobile ion concentration (n), ionic transference number (tion) have been carried out using different experimental techniques. The activation energy (Ea) values involved in the thermally activated conductivity processes have been computed from “log σ - 1/T” Arrhenius plots.