The presence of microorganisms in skin wounds can lead to infections that hamper the healing process; therefore, growing interest is given to the development of antimicrobial dressing. This study evaluates the ability of tea tree essential oil (EO) to eliminate resistant microorganisms, and new antibacterial bionanocomposites are prepared in two steps, namely sonication followed by melt mixing. Montmorillonite clay (MMT) and poly(acid lactic) (PLA) are chosen for constituting a polymer‐clay bionanocomposite for application in wound dressing. MMT retains and promotes a controlled release of the drug into the wound. Synthetic PLA is approved by the Food and Drug Administration for wound dressing applications. Disk diffusion tests evaluate the antimicrobial properties of tea tree oil, and X‐ray diffraction (XRD) and transmission electron microscopy (TEM) analyzed the extent of clay intercalation/exfoliation. Tea tree essential oil is effective against Escherichia coli and Staphylococcus aureus bacteria. According to the XRD results, the preparation method used can promote oil incorporation into the MMT galleries. TEM micrographs corroborated such results showing the coexistence of intercalated‐exfoliated structures in the bionanocomposites. As a conclusion, the produced bionanocomposites with tea tree essential oil are interesting antibacterial material to be used in wound dressing applications.