In this work, the solubilities of adipic acid, glutaric acid, and succinic acid in methanol + dimethyl glutarate mixtures were measured by using the laser dynamic method under 101.3 kPa at T = 287.05 to 337.35 K. The mass fraction of methanol in the solvent mixtures ranged from 1.0000 to 0.0000. The results showed that the measured solubilities would increase with increasing temperature at constant concentration, and it was also found that dimethyl glutarate had a negative effect on the solubilities. The Apelblat model, lambda h model, and nonrandom two liquid (NRTL) activity coefficient model were employed to correlate the experimental solubility data of binary solvent mixtures, and the correlated solubility by three models were proven to have good agreement with the experimental solubilities. Akaike information criterion (AIC) analysis results showed that the lambda h model was the most suitable model for predicting the solubility of succinic acid, adipic acid, and glutaric acid in the mixed solvent mixtures of dimethyl glutarate + methanol.