Solubilities of nonanedioic acid in binary ethanol + water solvent mixtures have been determined by the dynamic method using a laser monitoring observation technique over a temperature range from (292.35 to 345.52) K and a solvent composition, mole fraction of ethanol of solute-free x(2)(0), range from 0.0 to 1.0. The experimental results showed that in pure water the solubility of nonanedioic acid increased slowly with temperature below 342.77 K but increased significantly above 342.77 K. The nonanedioic acid + ethanol + water system was found to exhibit a synergistic effect on solubility. The fusion enthalpy and melting temperature of nonanedioic acid were measured by differential scanning calorimetry. The modified lambda h equation, the Wilson equation, and the NRTL equation have been applied to correlate a subset of the experimental data. These models can successfully describe the solubility of nonanedioic acid in the binary mixtures with an ethanol mole fraction higher or equal to 0.2811.