Photodynamic therapy (PDT) is a promising and minimally invasive method for the treatment of superficial diseases, and photosensitizers with high phototoxicity indices (defined as (IC50dark)/(IC50irradiation)) are essential for the development of ideal photosensitizing properties for this technology. Herein, we report a series of photocytotoxic copper(II) complexes Cu(RQYMP)(dppn) (RQYMP=N,N,O‐tridentate Schiff‐base derivatives, dppn=benzoidipyrido3,2‐a;2′,3′‐cphenazine), the structures of which have been confirmed by mass spectrometry and FTIR spectroscopy. X‐ray crystallography revealed that the CuN4O core of the Cu(cumylQYMP)(dppn)(ClO4) complex (3) has a distorted square‐pyramidal geometry. Phototoxicity indices of 329 against human squamous cell carcinoma (SCC15) and 296 against basal cell carcinoma (BCC) cell lines have been determined with Cu(3‐OMeQYMP)(dppn)(ClO4) (4). This can be attributed to the formation of reactive oxygen species, cell apoptosis, and caspase‐3 activation, indicating high potential of complex 4 as a photosensitizer candidate in PDT. Thus, copper complexes bearing suitable Schiff‐base ligands with a dppn co‐ligand may be considered for the design of efficient metal‐based anticancer agents for PDT. Copper complexes for PDT: Photocytotoxic copper(II) complexes Cu(RQYMP)(dppn) (RQYMP=N,N,O‐tridentate Schiff‐base derivatives, dppn=benzoidipyrido3,2‐a;2′,3′‐cphenazine) show high phototoxicity indices against SCC15 and BCC cancer cells owing to the generation of reactive oxygen species and caspase‐3‐mediated cell apoptosis.