Hosta is a genus of about 40 species of lily-like plants in the family Agavaceae, native to northeast Asia. The scientific name is also used as the common name; in the past they were also sometimes known as "Plantain lily", now obsolete. The Japanese name Giboshi is also used in English to a small extent.

They are herbaceous plants, with broad lanceolate leaves 6-50 cm long and 4-30 cm broad. The flowers are produced on an erect panicle up to 60 cm tall; the individual flowers are usually pendulous, 2-5 cm long, with six petals, greenish, white or pink in colour; richly perfumed in some species, but mostly scentless.

Hostas are notoriously a favourite food for slugs, which commonly cause extensive damage to hosta collections in gardens.