Taro (/ˈtɑːroʊ, ˈtær-/; Colocasia esculenta) is a root vegetable. It is the most widely cultivated species of several plants in the family Araceae that are used as vegetables for their corms, leaves, stems and petioles. Taro corms are a food staple in African, Oceanic, East Asian, Southeast Asian and South Asian cultures (similar to yams).

Colocasia esculenta is a perennial, tropical plant primarily grown as a root vegetable for its edible, starchy corm. The plant has rhizomes of different shapes and sizes. Leaves are up to 40 by 25 centimetres (15+1⁄2 by 10 inches) and sprout from the rhizome. They are dark green above and light green beneath. They are triangular-ovate, sub-rounded and mucronate at the apex, with the tip of the basal lobes rounded or sub-rounded. The petiole is .8–1.2 metres (2+1⁄2–4 feet) high. The path can be up to 25 cm (10 in) long. The spadix is about three fifths as long as the spathe, with flowering parts up to 8 millimetres (3⁄8 in) in diameter. The female portion is at the fertile ovaries intermixed with sterile white ones. Neuters grow above the females, and are rhomboid or irregular orium lobed, with six or eight cells. The appendage is shorter than the male portion.

Taro is among the most widely grown species in the group of tropical perennial plants that are colloquially referred to as "elephant ears", when grown as ornamental plants. Other plants with the same nickname include certain species of related aroids possessing large, heart-shaped leaves, usually within such genera as Alocasia, Caladium, Monstera, Philodendron, Syngonium, Thaumatophyllum, and Xanthosoma.

Taro is related to Xanthosoma and Caladium, plants commonly grown ornamentally, and like them, it is sometimes loosely called elephant ear. Similar taro varieties include giant taro (Alocasia macrorrhizos), swamp taro (Cyrtosperma merkusii), and arrowleaf elephant's ear (Xanthosoma sagittifolium).

The 18th-century Swedish biologist Carl Linnaeus originally described two species, Colocasia esculenta and Colocasia antiquorum, but many later botanists consider them both to be members of a single, very variable species, the correct name for which is Colocasia esculenta.

The Ancient Greek word κολοκάσιον (kolokasion, lit. 'lotus root') is the origin of the Modern Greek word kolokasi (κολοκάσι); the word for the plant is kolokas in Greek, gölevez in Turkish, and qulqas (قلقاس) in Arabic. These were borrowed by Latin as colocasia, thus becoming the genus name Colocasia. The specific epithet, esculenta, means "edible" in Latin.

The English name taro was borrowed from the Māori language when Captain Cook first observed Colocasia plantations in New Zealand in 1769. The form taro or talo is widespread among Polynesian languages: taro in Tahitian; talo in Samoan and Tongan; kalo in Hawaiian; taʻo in Marquesan. All these forms originate from Proto-Polynesian *talo, which itself descended from Proto-Oceanic *talos (cf. dalo in Fijian) and Proto-Austronesian *tales (cf. taleus in Sundanese & tales in Javanese). However, irregularity in sound correspondences among the cognate forms in Austronesian suggests that the term may have been borrowed and spread from an Austroasiatic language perhaps in Borneo (cf. proto-Mon-Khmer *t₂rawʔ, Khasi shriew, Khmu sroʔ, Mlabri kwaaj,...).

Colocasia esculenta is thought to be native to Southern India and Southeast Asia, but is widely naturalised. Colocasia is thought to have originated in the Indomalayan realm, perhaps in East India, Nepal, and Bangladesh. It spread by cultivation eastward into Southeast Asia, East Asia and the Pacific Islands; westward to Egypt and the eastern Mediterranean Basin; and then southward and westward from there into East Africa and West Africa, where it spread to the Caribbean and Americas.