Measurements of the relative fluorescence intensity and the lifetime of the excited states of the Ce3+ ions in an aqueous solution of cerium nitrate at various graphene oxide concentrations have shown that under the optical excitation of Ce3+ static quenching of fluorescence by graphene oxide takes place. The Stern-Volmer association constant of aquacomplex cerium with graphene oxide is measured to be 24.7 L/g. This value is much lower than the constants for cationic dyes of rhodamines and metal cations and is explained by the presence of negative charges on the interacting particles.