In this study, a novel experimental approach was used to overcome the lack of phase equilibrium information to obtain data that is more applicable to industrial situations. Liquid-liquid equilibrium (LLE) data, tie-lines, and phase boundaries were carried out for two systems of canola oil methyl esters (containing 1 wt % KOH) + glycerol + methanol and sunflower oil methyl esters (containing 1 wt % KOH) + glycerol + methanol at three different temperatures (303.15, 313.15, and 323.15 K). The quality of data was also ascertained using Othmer-Tobias correlations. The experimental LLE data was also correlated by the nonrandom two-liquid (NRTL) and the Wilson-NRF Gibbs free energy models. The energy interaction parameters of both models were obtained for both systems. The results indicated that the Wilson-NRF provided an accurate correlation of LLE behavior with average absolute deviation (AAD%) inferior to 8.78% and 10.80% for canola and sunflower biodiesel systems, respectively. However, the NRTL model presented a more accurate correlation of LLE behavior of both studied systems with AAD% inferior to 6.26% and 7.43% for canola and sunflower biodiesel systems, respectively.