Orange juice is susceptible to nutrient loss, non-enzymatic browning, and microbial proliferation during refrigerated storage. Plant-derived preservatives have been considered promising alternatives for reducing the use of synthetic chemical preservatives. To compare the effectiveness of fennel essential oil and two fennel oleoresins in maintaining the quality of refrigerated orange juice, fennel essential oil, ethanol-extracted oleoresin, and ethyl acetate-extracted oleoresin were individually added to orange juice at a concentration of 0.02% (φ). The treated juice samples were stored at 4 °C for 16 d. The pH, ascorbic acid content, titratable acidity, reducing sugar content, browning index, and total plate count were determined at 4-day intervals, and the overall quality was evaluated using principal component analysis (PCA). The results showed that the pH, reducing sugar content, non-enzymatic browning index, and total plate count increased across all treatment groups during storage, whereas the ascorbic acid content and titratable acidity decreased. On day 16, the total plate count in the ethanol control group (group B) reached 3.81 lg (CFU/mL), whereas those in groups C, D, and E were 3.41, 3.34, and 3.25 lg (CFU/mL), respectively, representing reductions of 60.6%, 66.7%, and 72.7% compared with group B. The pH of group E was 4.52, lower than that of group B (5.16), indicating that essential oil treatment effectively retarded the increase in pH during storage. The ascorbic acid content in group E was 17.30 mg/100 mL, which was 248.79% higher than that in group B (4.96 mg/100 mL). In addition, the reducing sugar content and non-enzymatic browning index of group E were 6.47 g/100 g and 0.30, respectively, compared with 7.00 g/100 g and 0.45 in group B, corresponding to decreases of 7.57% and 33.3%, respectively. Significant differences were observed between groups E and B for all of the above parameters (P<0.05). The titratable acidity of group E was 0.04%, lower than that of group B (0.12%), suggesting that the different treatments exerted distinct effects on changes in acidity during orange juice storage. Two principal components were extracted by PCA, accounting for 92.67% of the total variance. According to the comprehensive PCA scores, the treatments were ranked in the following descending order: fennel essential oil, ethyl acetate-extracted oleoresin, ethanol-extracted oleoresin, ethanol control, and untreated control. Quality deterioration in refrigerated orange juice was effectively delayed by fennel essential oil and fennel oleoresins. In conclusion, the greatest preservative effect was achieved with fennel essential oil, followed by ethyl acetate-extracted oleoresin. These findings provide a scientific basis for the screening and application of plant-derived preservatives for orange juice preservation.