Apium graveolens is a plant species in the family Apiaceae commonly known as celery (var. dulce) or celeriac (var. rapaceum), depending on whether the petioles (stalks) or roots are eaten: celery refers to the former and celeriac to the latter. Apium graveolens grows to 1 m tall. The leaves are pinnate to bipinnate leaves with rhombic leaflets 3–6 cm long and 2–4 cm broad. The flowers are creamy-white, 2–3 mm diameter, produced in dense compound umbels. The seeds are broad ovoid to globose, 1.5–2 mm long and wide.

First attested in English 1664, the word "celery" derives from the French céleri, in turn from Italian seleri, the plural of selero, which comes from Late Latin selinon, the latinisation of the Greek σέλινον (selinon), "parsley". The earliest attested form of the word is the Mycenaean Greek se-ri-no, written in Linear B syllabic script.

Celery was described by Carl von Linné in Volume One of his Species Plantarum in 1753.

The closely related Apium bermejoi from the island of Minorca is one of the rarest plants in Europe, with fewer than 100 individuals left.