Cedar (tree), common name for three or four species of large trees native to mountainous areas of North Africa and Asia. Cedar trees belong to the pine family, the members of which have needlelike leaves and, like all conifers, bear their seeds on scales clustered into cones. They differ from other members of the family in their evergreen four-angled leaves borne on short side-branches. The genus produces fragrant, durable, red-colored wood used in construction and cabinetry. Although no true cedars are native to North America, they are planted as ornamentals in milder areas, and various horticultural varieties, based on growth form and leaf color, exist.

The best-known cedar is the cedar of Lebanon, mentioned often in the Old Testament; the First Temple of Solomon was built of this wood (see 1 Kings 5:6). It is native to Asia Minor, and today only a few original groves remain, although they contain some trees of great age. Trees may reach 30 m (100 ft) in height and produce spreading branches that split off from the main trunk, unlike most conifers, which have a single dominant trunk. The dark to bright green leaves are about 2.5 cm (about 1 in) long, and the upright cones are about 10 cm (about 4 in) long. The Cyprus cedar, usually considered only a variety of the cedar of Lebanon, occurs on the island of Cyprus in the Mediterranean. The Atlas cedar is closely related to the cedar of Lebanon and occurs in the Atlas Mountains of North Africa. The remaining cedar, deodar, occurs in the Himalayas and is an important timber tree in India. Unlike the other species, which have horizontal branches and cones flat at the apex, the deodar has pendulous branches and rounded cones.

The name cedar is also applied to other conifer trees with fragrant wood (see Cypress). The well-known white cedar grows in swamps of the eastern United States and reaches a height of 24 m (80 ft). An arborvitae is also called cedar; western cedar and eastern white cedar are both important timber trees in the United States. Eastern red cedar, widespread in the eastern United States, is a juniper. A flowering tropical American mahogany is known as Spanish or West Indian cedar.

Scientific classification: Cedar trees belong to the family Pinaceae. The cedar of Lebanon is classified as Cedrus libani, the Cyprus cedar as Cedrus brevifolia, the Atlas cedar as Cedrus atlantica, and the deodar as Cedrus deodara. North American conifers called cedars belong to the family Cupressaceae: the white cedar is classified as Chamaecyparis thyoides, the western cedar as Thuja plicata, the eastern white cedar as Thuja occidentalis, and the eastern red cedar as Juniperus virginiana. Spanish or West Indian cedar is classified as Cedrela odorata of the family Meliaceae.