In the present study, we use a multiscale simulation approach to understand the mechanisms underlying the conductivity characteristics in single-ion conducting nanoparticle-based electrolytes. We identify the influence of nanoparticle volume fraction, anion and cation choices, and solvent (host) polarity on the ionic conductivity in such systems. Together, our results provide a complete picture for design considerations in single-ion conducting electrolytes based on nanoparticle salts. Direct computer simulations of the nanoparticle salt dispersions and their ionic conductivity characteristics using detailed molecular models are computationally intractable. To gain mechanistic insights, we instead adopt a novel approach that uses molecular dynamics (MD) and kinetic Monte Carlo (kMC) simulations to integrate information from length and time scales relevant for ion conduction (Figure and Supporting Information (SI)).