Chemically derived graphene holds great promise to boost the performance of photocatalysts because of its fascinating physical and chemical properties. Recently, tremendous efforts have been devoted to the design and synthesis of graphene-based composites for heterogeneous photocatalysis, with which remarkable progress has been achieved. This chapter presents a review of the latest developments of chemically derived graphene-based composites with improved photocatalytic properties. Beginning with a brief description of the challenges in photocatalysis research, we discuss the fundamental roles of chemically derived graphene in addressing these issues, followed by a discussion on the preparation of graphene-based composites for photocatalytic applications. Emphasis is then focused on enhancing the performance in terms of the degradation of pollutants, photocatalytic water splitting, and CO₂ reduction. Future directions toward the development of advanced graphene-based photocatalysts, perspectives, and challenges are outlined.