In this study, three antioxidants namely N,N′‐di‐sec‐butyl‐p‐phenylenediamine (PDA), 2,4,6‐Tri‐tert‐butylphenol/2,6‐Di‐tert‐butylphenol (IONOL), and unsaturated cardanol (U‐CDN) were added to babassu biodiesel (BB) at a concentration of 100 mg kg−1 to improve its oxidative stability. Differential Scanning Calorimetry (DSC) was used to evaluate the oxidative stability of the samples using synthetic air atmosphere and two temperatures (25 and 110 °C) instead of the conventional Rancimat method. The kinetic parameters were calculated according to Borchardt and Daniels method (ASTM E2041). All doped samples showed higher thermo‐oxidative stability when compared to pure babassu biodiesel with increasing activation energies of 66.5% for PDA, 19.4% for IONOL, and 3.9% for U‐CDN. At 25 °C, the babassu biodiesel showed a high oxidation reaction rate of 1.76 × 10−15 min−1. For the doped samples at the same temperature, that rate was reduced by a factor of 2, 200, and 3 × 108 times for U‐CDN, IONOL, and PDA, respectively. At 110 °C, the BB and the BB + U‐CDN samples showed high reaction rates, whereas the formulations with IONOL and PDA had rates reduced by 10 and 7.4 × 103 times, respectively. The thermal data showed R2 values higher than 0.99. All results confirmed the action of the antioxidants in retarding oxidation reactions in biodiesel. DSC is a promising alternative method for the determination of oxidative stability of biodiesel and its formulations with antioxidants.