In this study, Sargassum latifolium (S. latifolium) n-hexane extract as a novel source for insecticidal bioactive compounds was investigated. The composition of the extract was identified by using GC-MS analysis. We performed the study on four types of insects and larvae sp (Sarcophaga bullata, Tribolium castaneum, Musca domestica, and Solenopsis invicta) which cause a deleterious impact on the crops and human health. We used scanning electron microscopy to show the destructive effects of S. latifolium extract on the exoskeleton. The treatment exhibited severe morphological changes and a high mortality rate. Also, different bioinformatic approaches were utilized to investigate the possible insecticidal mechanism of the extract. Molecular docking showed the potential of the compounds to be chitin synthase inhibitors. Besides, the toxicokinetic parameters of the most promising compounds were evaluated to assess the impact of using the extract as an insecticidal agent on human health. S. latifolium extract exhibited promising insecticidal activity and acceptable toxicokinetic properties as compared to other known pesticide groups.