Abstract The quality and thermo-oxidative stability of soybean oil (SO), palm olein oil (POO), canola oil (CO) and their blends were evaluated. The binary blends of SO:POO and CO:POO were formulated in a ratio of (75:25) and ternary blend were prepared by blending CO:POO:SO in a ratio of (35:30:35). To monitor the thermal stability of pure oils and their blends, they were subjected to temperature (180°C) at different time intervals. The results revealed that at elevated temperature the quality of pure and blended oils deteriorate significantly. Heating process led to a substantial increase in free fatty acid (FFA), peroxide value (PV), p-anisidine value (p-AV), and saponification value (SV), while iodine value (IV) and oxidative stability index (OSI) decreased. However, blends comparatively showed better nutritional status and stability than the pure ones. The Principal component analysis (PCA) of all parameters was also performed. The data provide three significant principal components (PCs with eigenvalue ˃1), which collectively report 98.8% of the total variance. PC1 contributed mainly with total (50.1%) followed by PC2 (36.2%) and PC3 (12.5%) in the data. This work suggests that blending POO with other oils that contain more unsaturatation could be an effective and eco-friendly procedure which enhances the chemical sustainability and nutritional content of the oil.