An arboretum (plural: arboreta) in a narrow sense is a collection of trees only. Related collections include a fruticetum (from the Latin frutex, meaning shrub), and a viticetum, a collection of vines. More commonly, today, an arboretum is a botanical garden containing living collections of woody plants intended at least partly for scientific study. An arboretum specializing in growing conifers is known as a pinetum. Other specialist arboreta include salicetums (willows), populetums, and quercetums (oaks).

The term arboretum was first used in an English publication by John Claudius Loudon in 1833 in The Gardener's Magazine but the concept was already long-established by then.

Egyptian Pharaohs planted exotic trees and cared for them; they brought ebony wood from the Sudan, pine and cedar from Syria. Hatshepsut's expedition to Punt returned bearing thirty-one live frankincense trees, the roots of which were carefully kept in baskets for the duration of the voyage; this was the first recorded attempt to transplant foreign trees. It is reported that Hatshepsut had these trees planted in the courts of her Deir el Bahri mortuary temple complex.