Sodium iodide (NaI) is a water soluble ionic compound that consists of an equivalent addition of sodium as a cation (Na⁺) and iodide as an anion (I^-) in crystal space. It is industrially prepared by reacting acidic iodides with sodium hydroxide (NaOH) to form NaI salts. It is a less toxic compound than iodine and can be stored and handled easily.

NaI can be used as a precursor in the preparation of controlling agents for emulsion polymerization. It can also be used as an inorganic salt in the development of liquid electrolytes for the fabrication of dye sensitized solar cells (DSSCs).