As one of the most outstanding allotropes of carbon assembled with a cylindrical nanostructure, carbon nanotubes (CNTs) have attracted extensive attention in the areas of material science and engineering due to their unique structural characteristics and physicochemical properties. Very recently, versatile hierarchical CNT‐based photocatalysts are of considerable interest in current research and applications ranging from fuel generation to environmental purification. Therefore, it is necessary to summarize the CNT‐based photocatalysts to provide essential references for the continuous research study. In this review, the different design strategies and flexible functionalizations for prototype construction are described and their typical research, especially the structure‐related or electronic‐effected mechanism in the photocatalytic reaction of pollutants degradation, water splitting, and CO2 reduction overviewed. Finally, the various aspects of CNT‐based photocatalysts are discussed for future developments in commercial applications.