An accelerated oxidation assay was performed at 37 °C under dark conditions on binary blends of olive oil and hemp seed oil containing either 25% or 50% hemp seed oil (AC). The blends were fortified with tocopherols and gallic acid at several concentrations to evaluate their potential to modulate oxidative deterioration. Fortification with these antioxidants did not measurably alter classical primary quality parameters such as free acidity and peroxide valu, when compared with the corresponding non‑enriched controls. In contrast, the proportion of hemp seed oil itself was decisive: the higher inclusion level (50% AC) was associated with less favorable outcomes for both acidity and peroxide index, indicating an adverse effect on primary oxidative stability. A similar dependence on hemp seed oil content was recorded for the specific extinction coefficient at 232 nm (K232), which reflects conjugated dienes formed during early oxidation. Conversely, neither antioxidant enrichment nor hemp seed oil proportion produced discernible changes in the extinction coefficient at 270 nm (K270) linked to conjugated trienes and secondary oxidative species. Notably, the accumulation of secondary oxidation products increased with rising tocopherol dose, suggesting a pro-oxidant shift or depletion dynamics at elevated levels. Finally, the antioxidant capacity assays employed did not yield a straightforward correlation between measured oxidative stability and the compositional variables of the blends, underscoring the limitations of these in vitro methods for predicting real oxidative behavior in such complex lipid matrices.