Methylene blue (MB) was intercalated into layered potassium titanoniobate (KTiNbO5) through a guest–guest exchange method by use of the intercalation compound n-C4H9NH3+–TiNbO5 as a precursor. The MB+/H+–TiNbO5 nanocomposite has been characterized by XRD, SEM, IR, TGA, UV, elemental analysis, and electrochemical cyclic voltammetric measurements. From the XRD and elemental analysis results, we proposed that the MB+ cations formed a single layer standing vertically to the titanoniobate nanosheets together with H+. The CV curves of the MB+/H+–TiNbO5 nanocomposite thin film exhibited a fine diffusion-controlled redox process, which hints the possibility of being utilized as an electrode modifying material.