Edible antimicrobial films with essential oils are potential intervention strategies to improve microbiological safety of foods. The aim of this work was to study the effects of incorporating soybean oil (SBO) on the physical and antibacterial properties of alginate films prepared with 1% or 2% cinnamon bark oil (CBO). The incorporation of SBO improved the microstructure homogeneity and transparency, reduced tensile strength, elongation at break, water solubility, and total solids content but had no obvious effects on the water vapor permeability of films. Films prepared with 1% CBO had a low residual CBO after film formation and storage. For 2% CBO treatments, the addition of SBO reduced the loss of CBO during storage of films and improved the antimicrobial activity against Escherichia coli O157:H7, Listeria monocytogenes and Salmonella enterica. The results suggest that SBO can be used to improve certain physical characteristics and the antibacterial efficacy of edible films containing essential oils.