Hydrogen (H2) production using seawater is becoming increasingly popular due to the pressing need for sustainable and clean energy sources. Titanium dioxide (TiO2), known for its stability, low cost, and non-toxicity, exhibits promising performance in both photocatalytic and electrocatalytic processes. In photocatalytic water splitting, TiO2 utilizes solar or artificial light to initiate redox reactions, facilitating the production of H2 and oxygen (O2) from seawater. Various studies have investigated the factors influencing photocatalytic H2 production, including the concentration of ions and impurities in seawater, and have proposed methods to enhance efficiency. The current flows through the TiO2 electrode to split the water into its components, H2 and O2 in electrocatalytic water splitting. Recent studies have explored the TiO2-based electrocatalysts and their performance in diverse environments, revealing significant improvements in activity and stability. This chapter encapsulates recent research endeavors to advance TiO2-based catalytic systems as photocatalysts and electrocatalysts for seawater splitting, highlighting their potential in driving the transition towards an H2-based economy.