A vegetable oil is a triglyceride extracted from a plant. Such oils have been part of human culture for millennia. The term "vegetable oil" can be narrowly defined as referring only to plant oils that are liquid at room temperature, or broadly defined without regard to a substance's state of matter at a given temperature. For this reason, vegetable oils that are solid at room temperature are sometimes called vegetable fats. Vegetable oils are composed of triglycerides, as contrasted with waxes which lack glycerin in their structure. Although many plant parts may yield oil, in commercial practice, oil is extracted primarily from seeds.

On food packaging, the term "vegetable oil" is often used in ingredients lists instead of specifying the exact plant being used, especially when the oil used is less desirable to the consumer or if a mix is used.

Uses of triglyceride vegetable oil

Oils extracted from plants have been used since ancient times and in many cultures. As an example, in a 4,000-year-old kitchen unearthed in Indiana's Charlestown State Park, archaeologist Bob McCullough of Indiana University-Purdue University Fort Wayne found evidence that natives used large slabs of rock to crush hickory nuts, then boiled them in water to extract the oil.Archaeological evidence shows that olives were turned into olive oil by 6000 BC and 4500 BC in present-day Israel.