The stratum corneum, the outermost layer of the skin, is composed of corneocytes and intercellular lipids. The intercellular lipids mainly consist of ceramides, fatty acids, cholesterol, and cholesterol esters. These components form a bilayered lamellar structure, making it challenging for substances to penetrate. While oleic acid is known for its skin penetration enhancing properties, there is limited information about the skin penetration enhancing effects of oleic acid esters that focus on their structure. In this research, we investigated the potential skin penetration enhancing effects of various oleic acid esters, obtained by esterifying oleic acid with different alcohols, using excised human skin with ceramides as the target substance. As a result, we identified isobutyl oleate as a novel oil component with potential for cosmetic ingredient applications due to its skin penetration enhancing capabilities.