Little is known about how aqueous electrolyte exposure affects hydrated polymer relative permittivity and state of water properties. Increasing NaCl solution concentration (0.01, 0.1, and 1.0 mol/L) caused a cross-linked glycidyl and glycerol methacrylate-based copolymer to osmotically deswell and caused ion sorption to increase opposite to electrostatic theory and Maxwell Garnett equation predictions. The presence, due to salt solution equilibration, of ions in the polymer drove an increase in static permittivity compared to that of pure water-equilibrated equivalent water content samples. The influence of salt concentration on hydrated polymer dielectric permittivity properties was fundamentally different from its influence on aqueous electrolyte solutions where dielectric permittivity decreases as salt concentration increases. Generally, the amount of bulk-like water in the polymers decreased as salt concentration increased, but a maximum was observed in low water content (<7% by mass) polymers, suggesting that ions and water may compete for interactions with the polymer.