Chocolate is a food made from roasted and ground cocoa beans that can be a liquid, solid, or paste, either by itself or to flavor other foods. Cocoa beans are the processed seeds of the cacao tree (Theobroma cacao). They are usually fermented to develop the flavor, then dried, cleaned, and roasted. The shell is removed to reveal nibs, which are ground to chocolate liquor: unadulterated chocolate in rough form. The liquor can be processed to separate its two components, cocoa solids and cocoa butter, or shaped and sold as unsweetened baking chocolate. By adding sugar, sweetened chocolates are produced, which can be sold simply as dark chocolate, or, with the addition of milk, can be made into milk chocolate. Making milk chocolate with cocoa butter and without cocoa solids produces white chocolate.

Chocolate is one of the most popular food types and flavors in the world, and many foodstuffs involving chocolate exist, particularly desserts, including ice creams, cakes, mousse, and cookies. Many candies are filled with or coated with sweetened chocolate. Chocolate bars, either made of solid chocolate or other ingredients coated in chocolate, are eaten as snacks. Gifts of chocolate molded into different shapes (such as eggs, hearts, and coins) are traditional on certain Western holidays, including Christmas, Easter, Valentine's Day, and Hanukkah. Chocolate is also used in cold and hot beverages, such as chocolate milk, hot chocolate and chocolate liqueur.

The cacao tree was first used as a source for food in what is today Ecuador at least 5,300 years ago. Mesoamerican civilizations widely consumed cacao beverages, and in the 16th century, one of these beverages, chocolate, was introduced to Europe. Until the 19th century, chocolate was a drink consumed by societal elite. After then, technological and cocoa production changes led to chocolate becoming a solid, mass-consumed food. In the 21st century, cocoa beans for most chocolate are produced in West African countries, particularly Ivory Coast and Ghana, which contribute about 60% of the world's cocoa supply. The presence of child labor, particularly child slavery and trafficking, in cocoa bean production in these countries has received significant media attention.

Chocolate is a Spanish loanword, first recorded in English in 1604, and in Spanish in 1579. The word's origins beyond this are contentious. Despite a popular belief that chocolate derives from the Nahuatl word chocolatl, early texts documenting the Nahuatl word for chocolate drink use a different term, cacahuatl, meaning "cacao water". Several alternatives have therefore been proposed.

In one, chocolate is derived from the hypothetical Nahuatl word xocoatl, meaning "bitter drink". Scholars Michael and Sophie Coe consider this unlikely, saying that there is no clear reason why the 'sh' sound represented by 'x' would change to 'ch', or why an 'l' would be added. Another theory suggests that chocolate comes from chocolatl, meaning 'hot water' in a Mayan language. However, there is no evidence of the form 'chocol' being used to mean hot.

Despite the uncertainty about its Nahuatl origin, there is some agreement that chocolate likely derives from the Nawat word chikola:tl. Whether chikola:tl means 'cacao-beater', referring to whisking cocoa to create foam, is contested, as the meaning of chico is unknown. According to anthropologist Kathryn Sampeck, chocolate originally referred to one cacao beverage among many, which included annatto and was made in what is today Guatemala. According to Sampeck, it became the generic word for cacao beverages c. 1580, when the Izalcos from that area were the most notable producers of cacao.

Evidence for the domestication of the cacao tree exists as early as 5300 BP in South America, in present-day southeast Ecuador by the Mayo-Chinchipe culture, before it was introduced to Mesoamerica. It is unknown when chocolate was first consumed as opposed to other cacao-based drinks, and there is evidence the Olmecs, the earliest known major Mesoamerican civilization, fermented the sweet pulp surrounding the cacao beans into an alcoholic beverage.

Chocolate was extremely important to several Mesoamerican societies, and cacao was considered a gift from the gods by the Mayans and the Aztecs. The cocoa bean was used as a currency across civilizations and was used in ceremonies, as a tribute to leaders and gods and as a medicine. Chocolate in Mesoamerica was a bitter drink, flavored with additives such as vanilla, earflower and chili, and was capped with a dark brown foam created by pouring the liquid from a height between containers.