Water splitting is a promising method for hydrogen production, providing a clean energy source with a high energy yield. To meet long-term global energy demands, breakthroughs in hydrogen production, storage, and transportation are crucial. The direct use of seawater for hydrogen production is gaining popularity, as it reduces costs and efficiently utilizes saltwater resources. Technologies like photocatalysis, electrocatalysis, and photoelectrocatalysis facilitate seawater splitting by converting sunlight into hydrogen fuel, thus enabling green hydrogen production. For example, photocatalytic hydrogen generation mimics artificial photosynthesis, offering a simple and cost-effective approach. Our review of research on photo/electrocatalytic seawater splitting highlights both its limitations and future potential for sustainable fuel sources. Key challenges, such as low conversion efficiency and catalyst instability, need to be addressed. Future studies should focus on developing stable catalysts and optimizing mass transport at the electrode-electrolyte interface.