© 2022The antimicrobial resistance of Salmonella and other foodborne pathogenic bacteria, witnessed in recent years, has become a significant health concern. Bacteria use chemical signals to communicate each other and regulate their behavior including virulence. Due to increasing antibiotic resistance, new drug development strategies are being investigated and the use of active ingredients of various medicinal and aromatic plants as alternatives to antibiotics is tested. This study aimed to determine the anti-quorum sensing (QS) activity of cinnamon oil (CO) on Chromobacterium violaceum and to evaluate antimicrobial activity of CO against multidrug-resistant (MDR) Salmonella enterica serotypes. Anti-QS activity was tested using biosensor strain and antibacterial activity was determined by a microdilution method according to EUCAST standards. CO was found effective on QS system of Chromobacterium violaceum. Nineteen foodborne pathogens isolated from different poultry/cow sourced foods and serotyped as Salmonella enterica subsp. Enterica serotype Infantis (15), Kentucky (1), Newport (1), Telaviv (1), and Typhimurium (1). Salmonella Infantis strains were found resistant to three or more antibiotic classes (with resistance to at least one antibiotic from each class) and categorized as MDR. The results concluded that CO has strong antibacterial activity against all Salmonella enterica serotypes with MIC between 0.125 µg/ml and 1.0 µg/ml. This research demonstrates that CO is a potential candidate for developing new antimicrobial agents, antiseptic solutions or natural food preservatives against MDR Salmonella serotypes while is also a potential anti-QS agent.