In this study, chemical profile, antioxidant potential and antimicrobial interactions with conventional antimicrobials of essential oil (EO) isolated from Cladanthus scariosus aerial parts were investigated. The EO was analyzed by GC-MS (Gas Chromatography-Mass spectrometry). Forty-three components representing 98.7% of the oil were identified. The main components were o-cymene, caryophyllene oxide, γ-terpinene and α-sabinene. Furthermore, the antioxidant and antimicrobial activities against ten bacteria and two Candida strains were assessed. The results showed an interesting antioxidant effect with IC50 of 1.04 ± 0.04 mg/mL, 0.55 ± 0.01 mg/mL and 0.36 ± 0.14 mg/mL, respectively, for DPPH (2,2-Diphenyl-1-Picrylhydrazyl), FRAP (Ferric-Reducing-Ability-Power), and ABTS (2-2âazinobis-3-ethylbenzothiazoline-6-sulphonate) methods. The EO exhibited a strong antimicrobial activity, especially against Methicillin-resistant Staphylococcus aureus and Candida glabrata. In combination with antimicrobials, the studied EO revealed a high synergism effect in reducing gentamicin MICs of bacterial strains by 128- to 256-fold and by 2- to 8-fold Fluconazole MICs against Candida strains.