New photoactive material is obtained by chemisorption of carminic acid onto nanocrystalline titanium dioxide. Organic chromophore is anchored at the semiconductor surface via the neighboring carboxylate and phenolate groups; the anchorage is strengthened by formation of the six-membered chelate ring. Photoelectrochemical studies reveal strong photosensitization of the new material toward visible light: The photoelectrodes comprised of carminic acid−titanium dioxide hybrid material generate photocurrent within 300−650 nm window. Moreover, the direction of the photocurrent can be changed from anodic to cathodic and vice versa by application of appropriate photoelectrode potential, changes in electrolyte composition, and incident light wavelength. Geometry, electronic structure, and the photophysics of the neat chromophore and its model complex with TiIV oxo-species are studied in detail using the density functional theory method. Photoelectrochemical and spectroscopic studies supplemented with quantum-chemical modeling allow elucidation of photocurrent switching mechanism. The carminic acid−titanium dioxide material constitutes an efficient platform for light harvesting antennae, optoelectronic switches, and other optoelectronic devices.