Metal‐organic cages (MOCs) are a class of compounds formed through the coordination of metal ions with organic ligands to create well‐defined and cage‐like structure. These unique structures offer versatile environments for catalyzing a wide range of chemical reactions. The catalytic capabilities of MOCs are significantly influenced by the nature of the metal ions, functional ligands, and the cage structure. Notably, the confined spaces within MOCs can lead to enhanced reaction efficiencies, particularly in processes such as light‐induced hydrogen generation and the photocatalytic reduction of CO2. Furthermore, MOCs show great potential in photo‐organic synthesis due to the cage structure which provide a confined environment, and allow for encapsulating organic molecules, making them useful for improving the selectivity and efficiency of catalytic process. This review reports the development of MOCs for photocatalysis, focusing on the structural design and regulation strategy to build functional MOCs for photocatalytic hydrogen production, CO2 reduction, organic transformation. Insights into the photocatalysis are discussed including the challenges and further research direction in MOC‐based photocatalysis.