AbstractPlastic packaging derived from petroleum may have a negative impact on the environment when it is not properly recycled. Some studies present the use of biodegradable packages developed from natural polymers as a sustainable alternative; thus, the present work aimed to develop biodegradable sodium alginate films with antioxidant properties by the incorporation of carotenoid norbixin. Norbixin salts at the concentration of 0.01–0.05% were added to the sodium alginate films complexed with calcium ions. Carotenoid incorporation did not significantly impacted with the moisture content and the swelling capacity of the films. The thickness, water activity, and solubility were higher in the films with 0.05% addition of norbixin salts. The presence of the carotenoid improved the thermal stability of the films, as well as the water vapor barrier properties and lower ultraviolet–visible light transmission. However, the incorporation of 0.03% norbixin salts showed the best result for the analysis of antioxidant activity, with lower formation of oxidation products during sunflower oil storage and potential application for high fat foods.Practical ApplicationsResearchers aim to replace synthetic packaging by eco‐friendly packaging. The use of alternative materials such as polysaccharides, proteins, and lipids has been studied for the production of packaging susceptible to degradation under environmental conditions. Thus, the present work developed sodium alginate films complexed with calcium and incorporated with norbixin salts able to decrease sunflower oil oxidation.