This study investigates the phytotoxic effects of Elaeis guineensis essential oil of the seeds, extracted via Hot Water Floatation (HWF) approach with a yield of 20.7%, on plant growth. Bioassays demonstrated a concentration dependent reduction in both shoot and root lengths. At the lowest concentration (Treatment 1), shoot and root lengths were reduced by 21% and 29%, respectively, while higher concentrations in Treatments 2 and 3 led to reductions of up to 47%, with root growth consistently more affected. This heightened sensitivity in roots is likely due to their role as the initial site of uptake for phytotoxic compounds, resulting in oxidative stress, hormonal imbalance, and disrupted nutrient absorption. GC-MS analysis identified 14 compounds, including medium and long-chain fatty acids such as n-decanoic (14.88%), dodecanoic (9.49%) tetradecanoic (7.61%), and n-hexadecanoic acids (5.42%), comprising approximately 39% of the total oil. These fatty acids are known to compromise cell membrane integrity and impede physiological functions essential for germination and growth. The findings suggest that the essential oil of E. guineensis possesses significant allelopathic potential, with its fatty acid content being a primary contributor to its bioactivity. This highlights the oil's potential application as a natural bio-herbicide