The addition of alcohols to acetic acid and water mixture is effective for extracting acetic acid from the mixture. This work presents the liquid-liquid phase equilibrium (LLE) data of the ternary systems of 1-nonanol/acetic acid/water and 1-decanol/acetic acid/water measured at 298.2, 303.2, 308.2, and 318.2 K at 101.3 kPa. The effectiveness of the extraction process was quantified by the distribution coefficient (D) and selectivity (S). It was found that the extraction capability of 1-nonanol was superior to that of 1-decanol. We also used the Hand plot and the Othmer–Tobias plot to assess the reliability of the experimental LLE data, and the linear coefficient was greater than 0.99. The non-random two-liquid (NRTL) and the universal quasichemical (UNIQUAC) model were also used to correlate the experimental data. The Gibbs energy minimization method was used to evaluate the reliability of the regression parameters of the statistical model. The calculated root mean square deviation (RMSD) values were less than 0.023, indicating that both models were adequate for these systems.