Near‐infrared (NIR) responsiveness is important for various applications. Currently, single‐photon NIR‐responsive systems are rare compared to systems that display two‐photon absorption and triplet–triplet annihilation processes. Supramolecular stacking of photo‐responsive chromophores results in decreased efficiency due to space‐confinement effects. Herein we show that σ‐platination of pentacenes is a feasible protocol to build single‐photon NIR‐responsive systems, with advantages including a low HOMO–LUMO energy gap, high photochemical efficiency, and pathway specificity. The pentacene‐to‐endoperoxidation transformation is accompanied by color and absorbance changes. The high photo‐oxygenation efficiency of σ‐platinated pentacenes facilitates NIR responsiveness in one‐dimensional supramolecular polymers, resulting in the disappearance of supramolecular chirality signals and disruption of self‐assembled nanofibers. Overall, the σ‐platination strategy opens up new avenues toward NIR photo‐responsive materials at the molecular and supramolecular levels.