Cabbage (Brassica oleracea var. capitata) is a widely cultivated vegetable crop prone to several insect pests and fungal pathogens, leading to considerable yield losses. The present study investigates the bioefficacy of essential oil extracted from Eucalyptus globulus against fungal pathogens like Alternaria brassicae and Sclerotinia sclerotiorum. Laboratory bioassays and in vitro antifungal tests demonstrated that Eucalyptus oil possesses significant antifungal properties. The oil inhibited fungal mycelial growth in a dose-dependent manner. The findings suggest that Eucalyptus globulus oil could serve as a potential bio-based alternative to synthetic pesticides for sustainable cabbage production.