Selective activation of photocatalysts under constant light conditions has recently been targeted to produce multi‐responsive systems. However, controlled activation, with easy recovery of the photocatalysts, induced by external stimuli remains a major challenge. Mimicking the responsiveness of biological systems to multiple triggers can offer a promising solution. Herein, we report dual‐responsive polymer photocatalysts in the form of nanogels consisting of a cross‐linked poly‐N‐isopropylacrylamide nanogel, copolymerised with a photocatalytically active monomer. The dual‐responsive polymer nanogels undergo a stark decrease in diameter with increasing temperature, which shields the photocatalytic sites, decreasing the activity. Temperature‐dependent photocatalytic formation of NAD+ in water demonstrates the ability to switch photocatalysis on and off. Moreover, the photocatalysed syntheses of several fine chemicals were carried out to demonstrate the utility of the designed material. Responsive photocatalytic polymers: The inclusion of photocatalytic sites in a temperature‐responsive polymer nanogel network created a dual‐responsive polymer photocatalyst that can be utilised to selectively catalyse numerous reactions at specific temperatures.