As a semiconductor, MgWO₄ has a potential in photocatalytic applications; however, it has been overlooked in previous studies; in this study, it has been demonstrated that MgWO₄ exhibits the ability to drive photocatalytic hydrogen evolution. Compared to nanoparticle structures, MgWO₄ nanoplates show an increased photocatalytic ability due to their higher specific surface area. Moreover, the formation mechanism of MgWO₄ nanoplates has been discussed. An oriented attachment and ripening process is proposed for the formation of the MgWO₄ nanoplates. This study demonstrates that MgWO₄ can be considered a valuable photocatalytic material, and future studies should be focused on how to promote its photocatalytic conversion efficiency.