This research delved into examining the impact of hydrolysis and incorporation of Myrtle essential oil (MEO) on the film-forming and antimicrobial characteristics of ethyl cellulose polymer (EC). Three plasticizers (glycerol, mono ethylene glycol, and oleic acid) were evaluated for film-forming ability.T he composite biofilms' structure was assessed through SEM, XRD, FT-IR, and DSC. Eventually, the combination of hydrolyzed EC with oleic acid yielded a flexible film with optimal thickness. Utilizing GC-MS analysis, cx-pinene was identified as the predominant compound within MEO, conferring both antioxidant and antibacterial attributes. FTIR spectroscopy confirmed MEO's participation in the film forming matrix through hydrogen bonding.B y incorporating the MEO into the matrix, the WVP decreased significantly to 6.15*10-12 gmm/hmm2Pa considering that the hydrophobic feature of MEO can block the diffusion of water and decrease the WVP. The melting point and enthalpy of the polymer matrix containing MEO decreased that could be attributable to the EOs plasticizing impact, which increases the polymer chain mobility, and thereby hinders the strong interactions between polymer molecules. From the morphological finding, even at higher concentrations, MEO did not form agglomerations in the film matrix, highlighting its excellent compatibility with the microstructure of the resulting films.T he film containing MEO showed the acceptable antioxidant activity. Furthermore, films containing MEO substantially decreased S. aureus biofilm development at 24 and 48 h, compared to P. aeruginosa and E. coli. These findings suggest potential applications of the developed film in packaging and preservation.