This study developed a composite film for packaging refrigerated common carp fillets using carboxymethyl cellulose (CMC) (1.5 % w/v)/Myrrh gum (MG) (0.25 % w/v) base with the addition of titanium dioxide nanoparticles (TiO2 NPs) (0.25 %, 0.5 %, and 1 %) and Dill essential oil (DEO) (1.5 %, 2.25 %, and 3 %). The film was produced using a casting method and optimized for mechanical and barrier properties. The incorporation of DEO and TiO2 NPs into CMC/MG composite films significantly reduced moisture content (MC) and water vapor permeability (WVP), improved their tensile strength (TS), and increased their antimicrobial and antioxidant properties. Moreover, MG can improve the physicomechanical properties of the CMC/MG composite films. The film components had good compatibility without significant aggregation or cracks. In conclusion, the optimized CMC/MG (1.5 %/0.25 %) film containing TiO2 NPs (0.5 %), and DEO (2.25 %) has the best overall performance and can be a good source for making edible film. Functionally, this bioactive nanocomposite film significantly increased the shelf life of refrigerated fish fillet samples for 12 days by inhibiting microbial growth and reducing the oxidation rate compared to the control sample. The knowledge obtained from this study can guide the development of bio-nanocomposite and biodegradable food packaging films based on CMC/MG to increase the shelf life of food products and environmental protection.