The present investigation aimed to determine the oxidative potential, sun protection factor value, and half-maximal inhibitory concentration of rosemary essential oil and tea tree essential oil. These two essential oils have gained popularity as active ingredients in many cosmetic preparations due to their antioxidant activity, whether used individually or in combination. Gas chromatography-mass spectroscopy is used to identify the presence of different phytochemical constituents in essential oils. The GC-MS (Gas chromatography-mass spectroscopy) chemical analysis of tea tree oil revealed 34 and rosemary oil revealed 35 volatile chemical components with sesquiterpene hydrocarbon, monoterpenes (42.77%), and alcohols (41.01%) as major detected classes. The 2, 2-diphenylpicrylhydrazyl (DPPH) and nitric oxide-free scavenging activity techniques were used to investigate the antioxidant capacity of these oils. It was found that both tea tree and rosemary oil have the potential to slow down skin aging through their anti-oxidative properties using the approach of free radical scavenging activity. The UV spectroscopy method was used to determine the sun protection factor, and the sun protection values of rosemary and tea tree oil were found to be 8.45 and 6.85, respectively. Rosemary oil was an extremely promising tea tree essential oil for anti-aging and sunburn prevention. The study's findings indicated that rosemary and tea tree essential oil can both offer a synergistic sun protection factor effect, antioxidant property, and anti-aging or extra activity of cosmetic preparations.