A hybrid photothermal catalytic system, which combines both the photochemical (light) and thermal (heat) activation pathways over a bifunctional catalyst, has demonstrated remarkable levels of reaction activity and selectivity when compared with individual photocatalysis and thermocatalysis. However, the complex nature of the hybrid system, coupled with the synergy between photocatalysis and thermocatalysis, has made it challenging to understand (and thus manipulate) the role of individual stimuli (light/heat) and catalyst surface processes. In this perspective, a systematic classification for different (complicated) photothermal catalysis reaction systems is provided. We evaluate the singular catalytic characteristics of each category, together with the competence of light-heat dual activation in overcoming the well-defined limitations in photocatalysis and thermocatalysis, mainly in the scope of C1 chemistry. Notably, the interplay and cooperation among heat and/or light-induced effects can be engineered to greatly extend the capability of chemical transformation (i.e., product selectivity and reactivity) via the well-established photo-thermo cascade reaction. Finally, we provide critical insights into the catalyst development and reactor design for high-performance light-heat-coupled catalytic systems.