<p>Ferrofluids are innovative functional media combing magnetic nanoparticles with liquid fluidity. In this study, a hydrophobic deep eutectic solvent-ferrofluid was prepared by dispersing oleic acid-coated magnetic nanoparticles in hydrophobic deep eutectic solvent composing of DL-menthol and lauric acid, and applied for magnetic assisted liquid–liquid microextraction of trace polycyclic aromatic hydrocarbons (PAHs) from water and food samples. Following microextraction, phase separation was achieved rapidly using an external magnetic field, eliminating the need for time-consuming steps such as centrifugation or ice baths. The material’s structure was characterized by X-ray diffraction and infrared spectroscopy, while its magnetic properties were examined with a vibrating sample magnetometer. Extraction parameters were systematically screened and optimized using Plackett–Burman and Central Composite design experiments. Under optimized conditions, the limits of detection and quantification were 0.05–0.2&#xa0;µg L^− 1 and 0.1–0.5&#xa0;µg L^− 1, respectively, with intra-day and inter-day relative standard deviations (<i>n</i> = 5) below 1.6% and 1.7%. The extraction mechanism was further explored using density functional theory. Then, this method was successfully applied to determine of PAHs from environmental water and food samples, achieving spiked recoveries of 85.9–103.0%. Its greenness and practical applicability demonstrate its potential for food analysis and environmental monitoring.</p>