This study evaluates the effects of chitosan/clove essential oil nanoemulsion antioxidant films (CH-CEON) on the oxidative stability and quality of chilled mirror carp fillets. During storage, increased lipid and protein oxidation of all samples was observed, which resulted in a darker color, a softer texture, and increased water loss. Compared to the control, the oxidation and quality deterioration were inhibited in other samples, with the best effect was observed in those treated with CH-CEON. The peroxide value, thiobarbituric acid reactive substances (TBARS), total viable count, pH, total volatile basic nitrogen (TVB-N), b*, centrifugal, and cooking loss of samples treated with CH-CEON were 20.8%, 37.4%, 20.6%, 4.5%, 58.8%, 13.5%, 23.4%, and 11.1% lower than the control at 12 days, respectively. Conversely, the active and total sulfhydryl content, L*, a*, and whiteness (W) increased by 64.4%, 31.9%, 13.4%, 186%, and 15.3%, respectively. The texture of the treated samples was improved, and the shelf life was extended by 5 days. These changes were attributed to the slow release of phenolics in the films, which inhibited oxidation and quality deterioration of fish by scavenging free radicals. Moreover, the nanoemulsion increased the contact between clove essential oil (CEO) and samples, adsorbing free radicals more efficiently. This highlights the significant potential of CH-CEON for application in fish preservation.