Abstract: To address the issue of fishy odor in farmed sea bass, this study investigated the effects of seasoning treatments using extracts from three medicinal and edible plants—oregano, citronella, and moringa oleifera—and their compound mixture, on fish flavor profiles. Flavor characteristics were analyzed via electronic nose, electronic tongue, free amino acid analysis, and headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME-GC-MS). Results demonstrated that all seasoning solutions applied at a concentration of 0.3% (w/w) effectively improved the flavor quality of sea bass fillets. Notably, the compound treatment group (oregano:citronella:moringa oleifera=1:1:1) exhibited a synergistic effect. Seasoning treatments significantly reduced (P<0.05) thiobarbituric acid (TBARS) values in fish muscle, indicating effective retardation of lipid oxidation. Concurrently, increased total color difference (ΔE) values resulted in visibly darker coloration. E-nose analysis revealed that seasoning treatments significantly attenuated sensor response values for W1W (sulfides), W2W (organosulfides), and W1S (methyl groups), corresponding to reduced levels of sulfur-containing compounds and methyl-derived off-flavors associated with fishiness. Principal component analysis (PCA) effectively discriminated among the five sample groups. E-tongue detection indicated significantly reduced acidity and bitterness values in all treatment groups compared to the control (P<0.05). The compound treatment significantly increased the total free amino acid content from 357.94 mg/100 g to 418.96 mg/100 g (P<0.05), with a marked increase in umami-related amino acids. This suggested that the seasoning treatments effectively promote amino acid release, thereby enhancing nutritional value. GC-MS analysis demonstrated a significant increase in the diversity of volatile compounds in seasoned fish. Specifically, the number of volatile compounds in the compound seasoning treatment group increased from 19 (control) to 45 types, with notable increases in alcohols and terpenes. Aldehyde content decreased, and the primary fishy odor compound, hexanal, was substantially reduced from 3207.03 μg/kg to 317.67 μg/kg. The study demonstrates that these three natural extracts, particularly in combination, can reduce the generation of fishy odor substances through multi-pathway synergistic effects, providing theoretical support for the application of natural substances in flavor enhancement of aquatic products.