The Libyan coasts provide a diverse environment with many seaweeds that are unstudied. The present study was conducted with the aim of evaluating the effect of irrigation with seawater at several concentrations (0, 10, 20, 30and 40%) on the germination of seeds of Ceratonia siliqua L. (wild and cultivated), and treatment by pre-soaking for 24 h at a concentration 10% of three species of seaweed extracts (Padina pavonica, Sargassum vulgare, and Posidonia oceanica ). The results showed that C. siliqua seeds were able to germinate under until a concentration of 30% by a germination percentage (18%). Generally, salinity stresses significantly decreased germination percentage, delayed its mean germination time, and reduced radical lengths. The statistical results suggest that there were highly significant differences in increasing the germination percentage, shortened mean germination time, and increased radical length and the seeds treated with seaweed extract could tolerate 40% salinity. P. pavonica was observed as more efficient in reducing the adverse effects of seawater salinity. The results showed no significant differences between wild and planted C. siliqua seeds for all studied traits. The study concluded that seaweeds could be used as a promising bio-stimulant in agricultural development fields.