(Bio)chemical and industrially relevant reactions occur predominantly in the liquid phase. The influence of solvent on reaction rates was first documented by Berthelot and Pean de Saint-Gilles in 1862 and later formalised by Menschutkin in 1890. Since then, experimental and computational techniques have been developed to elucidate and quantify the origin of solvent effects on reactivity and selectivity. From an atomistic point of view, solvent effects arise from the interactions between solute and solvent molecules, which, although generally weak, have a significant impact on the overall reaction dynamics.