<p>A decanol–tetrahydrofuran supramolecular solvent (SUPRAS)–based vortex-assisted salt-saturated microextraction method coupled with UV–Vis spectrophotometry was developed for the determination of quercetin in real samples. The extraction efficiency was significantly enhanced by salt saturation, resulting in a 45.5% increase in analytical signal compared with the same SUPRAS-based procedure without salt addition. The effects of extraction solvent volume, pH, tetrahydrofuran volume, centrifugation speed and time, and vortex time were optimized using response surface methodology and one-variable-at-a-time approaches. Under optimal conditions, the method exhibited a linear dynamic range of 0.001–5.0 mg L⁻¹, with limits of detection and quantification of 0.28 µg L⁻¹ and 0.97 µg L⁻¹, respectively. An enrichment factor of approximately 136 was achieved. The proposed method showed good precision (RSD &lt; 3.7%) and accuracy. Applicability was confirmed by analysis of fish, apple and tomato samples, yielding recoveries in the range of 96.9 to 100.0%. Owing to its simplicity, low solvent consumption, and satisfactory analytical performance, this method provides an efficient and environmentally friendly approach for routine spectrophotometric determination of quercetin.</p>