Traditional emulsions consist of two or more immiscible phase systems, where one liquid is dispersed as small droplets in the other. Oleogel-structured emulsions (OGEs) are a novel type of emulsion system. They are prepared by incorporating food-grade gelling agents into the liquid oil phase of traditional emulsions; after crystallization or self-assembly, the gelling agents solidify to form a three-dimensional network structure that encapsulates the liquid oil. Consequently, OGEs can be used as substitutes for plastic fats, combining the health benefits of liquid oils (reducing trans and saturated fatty acids) with the advantages of solid fats: facilitating texture formation (e.g., in ice cream and margarine), restricting oil droplet migration, blocking oxygen, and delaying fat digestion. Currently, OGEs have been widely applied in the encapsulation of bioactive substances. Compared with traditional emulsions, OGEs exhibit superior stability and higher encapsulation and delivery efficiency. This review summarizes the preparation methods, physicochemical properties, and food applications of OGEs. It aims to explore the mechanisms of OGEs for encapsulating bioactive substances or nutritionally functional ingredients, provide strategies for replacing solid fats in specific foods and constructing efficient and stable emulsion-based delivery systems for bioactive substances, enhance the stability and bioavailability of encapsulated substances, and lay a theoretical foundation for their applications in the food, pharmaceutical, and cosmetic industries.