The aim of this study was the phytochemical characterization of essential oil extracted from the aerial parts (stems, leaves, and flowers) of Ammoides pusilla (Brot.) Breistr (APEO) by use of GC–MS. Importantly, GC–MS results revealed that APEO oil composed of 10 terpene compounds, of which carvacrol (52.84%), d-limonene (17.78%), β-Cymene (13.18%) and γ-Terpinene (8.46%) predominate. These compounds are recognized for their important biological properties. APEO demonstrated remarkable antimicrobial activity, outperforming positive controls in all cases. Inhibition diameters ranged from 30.20 mm against Candida glabrata to 49.80 mm against Candida albicans, with minimum inhibitory concentrations (MICs) ranging from 0.25% against Staphylococcus aureus and Micrococcus luteus to 4.00% against Candida glabrata. This antimicrobial efficacy is attributed to the oil's rich bioactive molecules. The essential oil also showed significant dose-dependent inhibition of anti-tyrosinase activity, with IC50 of 29.59 ± 1.89 µg/mL for monophenolase activity and 17.56 ± 0.76 µg/mL for diphenolase activity. At the same time, APEO showed significant inhibition of elastase, with an IC50 of 20.90 ± 3.16 µg/mL. The sun protection factor (SPF) of the essential oil was determined to be 4.323. This SPF value corresponds to an estimated 76.88% effectiveness in blocking UVB radiation. These results suggest that APEO possesses promising dermatoprotective and anti-aging properties. In conclusion, APEO exhibits notable antimicrobial, anti-tyrosinase and anti-elastase activities, paving the way for new natural therapeutic options for skin problems, with anti-aging and dermatoprotective dermal applications.