Herein, we report a facile synthesis of sodium niobiate (NaNbO₃) perovskite nanomaterial using a solid-state reaction (SSR) via solvothermally grown niobium pentoxide (Nb₂O₅) nanopowder for the excellent sensitive detection of dopamine (DA) in simulated blood serum with high selectivity. The X-ray Diffraction (XRD) pattern and Raman spectrum revealed an orthorhombic phase formation for NaNbO₃ and the presence of a NbO₆ octahedra site, while the scanning electron microscopy (SEM) images confirmed berry-like cluster formations of NaNbO₃. The NaNbO₃ modified glassy carbon electrode (GCE) sensor showed an excellent selectivity against interfering species like Na⁺, Cl⁻, Ca²⁺, glucose, ascorbic acid (AA), anduric acid, a sensitivity of 99 nA nM⁻¹ cm⁻² in the wide dynamic range of 10 nM to 500 μM, and a limit of detection (LOD) of 6.8 nM towards DA sensing, making it suitable for detecting physiological levels of DA in human blood. The sensing mechanism for DA was ascribed to the presence of NbO₆ octahedral sites in the NaNbO₃ perovskite structure that interacted with the oxidase of DA (dopamine-o-quinone) through Nb⁵⁺/Nb⁴⁺ niobium states, resulting in an increase in the oxidation peak current. This sensor did not exhibit any kind of surface fouling effects due to the reduction mechanism and the Na⁺ ions stabilizing the perovskite structure. The as-fabricated NaNbO₃/GCE sensor was further assessed for the detection of DA in simulated blood serum, which showed an excellent recovery percentage. This novel, binder-free, NaNbO₃ perovskite-based modified electrode offers a promising platform for developing high performance, non-enzymatic electrochemical sensors for numerous bioanalytical applications.