Juice is a beverage made from the extraction or pressing out of the natural liquid contained in fruit and vegetables. It can also refer to liquids that are flavored with these or other biological food sources such as meat and seafood (e.g., clam juice). Juice is commonly consumed as a beverage or used as an ingredient or flavoring in foods or other beverages, such as smoothies. Juice emerged as a popular beverage choice after the development of pasteurization methods allowed for its preservation without using fermentation (the approach used with wine production). The Food and Agriculture Organization of the United Nations (FAO) estimated the total world production of citrus fruit juices to be 12,840,318 tonnes in 2012.  The largest fruit juice consumers are New Zealand (nearly a cup, or 8 ounces, each day) and Colombia (more than three quarters of a cup each day). Fruit juice consumption on average increased with country income level.  To the American food industry, fruit juice is more profitable than only fruit.

The word "juice" comes from Old French in about 1300; it developed from the Old French words "jus, juis, jouis", which mean "liquid obtained by boiling herbs". The "Old French jus "juice, sap, liquid" (13c.)... [came] from Latin ius [which means] "broth, sauce, juice, soup," from PIE root *yeue- "to blend, mix food" (cognates: Sanskrit yus- "broth," Greek zyme "a leaven," Old Church Slavonic jucha "broth, soup," Russian: уха "ukha", Lithuanian: juse "fish soup")."  The use of the word "juice" to mean"the watery part of fruits or vegetables" was first recorded in the early 14th century. Since the 19th century, the term "juice" has also been used in a figurative sense (e.g., to mean alcohol or electricity). Today, "au jus" refers to meat served along with its own juice, commonly as a gravy.

Juice is prepared by mechanically squeezing or macerating (sometimes referred to as cold pressed) fruit or vegetable flesh without the application of heat or solvents. For example, orange juice is the liquid extract of the fruit of the orange tree, and tomato juice is the liquid that results from pressing the fruit of the tomato plant. Juice may be prepared in the home from fresh fruit and vegetables using a variety of hand or electric juicers. Many commercial juices are filtered to remove fiber or pulp, but high-pulp fresh orange juice is a popular beverage.