Oleic acid is a monounsaturated omega-9 fatty acid abundant in olive oil, avocados, and animal fats. It plays a key role in cell membrane fluidity, acts as a precursor for longer-chain fatty acids, and exhibits anti-inflammatory properties. Industrially used in soaps, cosmetics, and as an emulsifier. Chemically, it features a cis double bond at position 9, conferring liquidity at room temperature compared to saturated analogs. It is biosynthesized via desaturation of stearic acid and participates in lipid metabolism pathways. In food science, it contributes to flavor stability and nutritional value of edible oils.