Solubilities of benzoic acid, p-methylbenzoic acid, o-phthalic acid, m-phthalic acid, and terephthalic acid in isobutyl acetate were measured in the temperature range from (299.73 to 353.15) K. The solubility data showed notable distinction in terms of different orders of magnitude. The experimental data were correlated by the universal quasichemical activity coefficient (UNIQUAC) model and the Wilson model. Generally, the UNIQUAC model was slightly superior to the Wilson model.