This study investigated the production of hydrogen over Ga (1.0, 2.0, and 5.0 mol%)-$TiO_2$ photocatalysts prepared by a solvothermal method. The absorption band was slightly blue-shifted upon the incorporation of the gallium ions, but the intensity of the photoluminescence (PL) curves of Ga-incorporated $TiO_2$s was distinguishably smaller, with the smallest case being the 2.0 mol% Ga-$TiO_2$, which was related to the recombination between the excited electrons and holes. $H_2$ evolution from photo splitting of water over Ga-incorporated $TiO_2$ in the liquid system was enhanced, compared to that over pure $TiO_2$; particularly, the production of 5.6 mL of $H_2$ gas after 8 h when 1.5 g of the 2.0 mol% Ga-incorporated $TiO_2$ was used.