Bio-based thermoset polymers were produced from epoxidized waste vegetable oils cured with anhydrides at different molar ratios. Properties were compared to analogues produced with neat oil and DGEBA as a feedstock. Thermal stability proved to be affected by the molar ratio, and the use of feedstock from waste oil resulted in no effect on this property. DMA has shown that higher concentrations of anhydride enhance the storage modulus, Tg (up to 42.5 °C) and crosslink density. The frying process proved to play a minor role in tuning the dynamic-mechanical properties. However, the contribution of the anhydride demonstrated to be significant enough to mitigate the losses caused by the waste oil, as shown statistically in a DOE study. All formulations were chemically resistant to aqueous, organic and acidic media. The identification of the effects of critical parameters on the properties of WVO-based thermosets enables further production of polymers from waste streams