Acne vulgaris is a common inflammatory skin disorder that often requires long-term topical therapy; however, conventional formulations are limited by poor skin penetration, instability of active ingredients, and local irritation. Tea tree oil–loaded transethosomal gel can enhance topical anti-acne delivery. Transethosomes were prepared by the cold method using soya lecithin, cholesterol, ethanol, and Span 80, incorporating different concentrations of tea tree oil. The formulations were evaluated for vesicle size, organoleptic properties, drug content, pH, spreadability, in vitro permeation, and antibacterial activity against acne-causing microorganisms. The developed transethosomes showed nanosized vesicles with good uniformity, indicating enhanced deformability and suitability for dermal penetration. The transethosomal gel exhibited acceptable pH, good homogeneity, satisfactory spreadability, and efficient washability. In vitro permeation studies demonstrated improved drug diffusion compared to conventional gel systems, while antibacterial studies showed notable inhibitory activity against, Propionibacterium acnes confirming enhanced antimicrobial efficacy of the formulation. Overall, the results suggest that tea tree oil–loaded transethosomal gel is a promising, non-invasive delivery system that improves stability, skin permeation, and therapeutic potential of herbal anti-acne agents. This novel formulation strategy offers an effective alternative for topical acne management with improved efficacy and patient compliance.