Clay materials including clay minerals and layered double hydroxides (LDHs) have attracted great attention because of their special layer structures, large specific surface areas, and remarkable adsorption capacities. In the past few decades, they have been regarded as important components or precursors for making various functional materials. This paper aims to review and summarize the recent advances in the synthesis and photocatalytic applications of clay-based photocatalysts. Moreover, the effects of surface and structural characteristics of clay-based photocatalysts on photocatalytic properties are also discussed. The clay-based photocatalysts show good application prospects for environmental remediation and energy conversion. Especially, H2 generation and reduction of CO2 into carbon sources can be easily achieved using the LDH-based photocatalysts. Meanwhile, the role of clay materials in the photocatalysis is discussed in detail.