The development of clean and renewable energy has been recently receiving great interest because of increasing environmental concerns and depletion of conventional fossil fuels. Photocatalytic water splitting is considered as a low-cost and high-efficiency technology for the generation of green hydrogen (H2) fuel. In the present study, we successfully prepared cobalt-aluminum layered double hydroxides/reduced graphene oxide (CoAl-LDHs/RGO) nanocomposites via a simple solvothermal method and used them as photocatalytic materials for H2 production by water splitting. The photocatalytic water splitting result indicated that the as-prepared CoAl-LDHs/RGO nanocomposites displayed enhanced H2 production of 1571.84 μmol h-1 g-1 in the presence of a ruthenium (Ru) photosensitizer as compared with pure CoAl-LDHs (430.14 μmol h-1 g-1) under visible-light irradiation. This enhanced performance of CoAl-LDHs/RGO nanocomposites was mainly due to the efficient transfer and separation of photo-generated charge carriers by a strong electronic coupling effect at the interface of CoAl-LDHs and RGO. Therefore, the obtained CoAl-LDHs/RGO nanocomposite can be a promising photocatalytic material for energy harvesting and environmental remediation.