Renewable and clean energy supplies are highly critical for the reduction of greenhouse emissions and environmental pollution to realize a sustainable society. Among various techniques for using sustainable energy sources, such as solar energy, photocatalysis plays a crucial role in solving global problems, such as the energy crisis and environmental pollution. Thus, the design and development of Earth-abundant, low-cost, high-performance photocatalysts for water splitting and wastewater treatment are critical. Among these photocatalysts, RuddlesdenPopper (RP) perovskites have attracted increasing attention in photocatalysis as a result of their unique structural, electronic, and optical characteristics. In this review, the recent advances of RP perovskites in photocatalysis are presented. The review begins with an introduction of the unique features of RP perovskites that are suitable for photocatalysis, which is followed by a discussion of the use of typical RP-type perovskite oxides as photocatalysts by highlighting several useful design strategies. Finally, the conclusions of this review, along with current challenges and future directions for the design of RP perovskites for photocatalysis, are presented and discussed. This review aims to provide helpful guidance for the future development of RP-type perovskite oxides for photocatalysis-based water splitting and wastewater treatment.