Abstract Transformation of light energy into chemical energy through supramolecular assemblies is a major pathway for energy harvesting in natural systems. An anionic azobenzene photoswitch assembled with a light‐absorbing dendrimer via non‐covalent interactions such as anion‐π motifs transfer the absorbed light to the bound photoswitch. The energy transfer was used for trans→cis photoisomerization of the photoswitchable system. The photoisomerization rate in the dendrimer−azobenzene assembly was found to be faster compared to the azobenzene itself.