SummaryPostharvest decay of blueberry fruits caused by Fusarium oxysporum (F. oxysporum) results in significant losses during logistics. To avoid chemical residue issues associated with synthetic fungicides, present study investigated the antifungal activity of Cinnamomum camphora essential oil (CEO) against Fusarium oxysporum (F. oxysporum) in postharvest blueberry fruits. CEO effectively disrupted cell membrane integrity, impaired ergosterol structure, restricted ATPase activity and inhibits mycelial growth. Blueberries treated with a 0.2% CEO‐based coating demonstrated improved overall sensory acceptability, enhanced firmness, increased total soluble solids and titratable acidity, and reduced decay rate. CEO also decreased malondialdehyde contents while promoting ascorbic acid and glutathione levels and activating antioxidant enzymes, such as superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD), maintaining cell membrane structure and enhancing resistance against F. oxysporum infection. The findings suggest that CEO serves as an eco‐friendly agent for mitigating primary fungal invasion in blueberries during postharvest storage.