Here, we reveal the impact of hydration on the ionic conductivity modification of cations and anions under vibrational strong coupling. We conducted a systematic study on alkali metal halide solutions and observed an increase in the ionic conductivity as a result of hydration modification. We propose a mechanism in which vibrational strong cou-pling is employed to modify hydration dynamics. Importantly, the nature of hydration, whether positive or negative, has an influence on the modifications of ionic conductivity.