Seaweed is the general term for marine algae. It is the algae growing in the sea. There are various of bioactive substances in the seaweed which have been proved to have acceptable neuroprotective functions. Among studies to date, drugs for neurodegenerative diseases treatment have detrimental side effects in vivo. Furthermore, in recent years, insomnia is afflicting people of different ages as a intractable precursory problem of neurasthenia and neurodegenerative. In this review, we first summarized the effects and mechanisms of different seaweed bioactive compounds on neurodegenerative disorders, then discussed the effects on insomnia. The various seaweed bioactive compounds were finally confirmed to be effective on neuroprotection, which in turn may provide thoughts for further research on potential dietary therapeutic strategy for insomnia.