is a tree with various applications. Desertification and salinity are major constraints to crop productivity worldwide, especially in Saudi Arabia. Therefore, it is essential that plants alleviate and adapt to salt stress. Many physiological, pharmacological, and molecular strategies are employed by plants to lessen the effects of salinity stress. In this work, plants were grown under different salinity levels and treated with a foliar spray of seaweed extract to evaluate the fixed oil using GC/MS analysis, free proline and total soluble proteins using colorimetric methods, total phenolic content using Folin-Ciocalteu phenol reagent, total flavonoids using a spectrophotometric method, and antioxidant activity using the DPPH method. The study has shown that applying seaweed extract to plants grown under different salinity conditions improves seed oil yield, proline levels, soluble proteins, phenolic content, flavonoids, and antioxidant activity. As salinity increases, the oil yield decreases, but the levels of proline, phenols, flavonoids, and antioxidant activity rise. Seaweed extract application also reduces protein breakdown and boosts osmoprotectants. Salt stress decreases unsaturated fatty acids like oleic acid and increases saturated fatty acids like stearic acid. Overall, seaweed extract helps mitigate the adverse effects of salinity, enhancing oil yield and stress resistance in moringa trees.