Hornbeams are hardwood trees in the plant genus Carpinus in the family Betulaceae. Its species occur across much of the temperate regions of the Northern Hemisphere.

The common English name hornbeam derives from the hardness of the woods (likened to horn) and the Old English beam, “tree” (cognate with Dutch Boom and German Baum).

The American hornbeam is also occasionally known as blue-beech, ironwood, or musclewood, the first from the resemblance of the bark to that of the American beech Fagus grandifolia, the other two from the hardness of the wood and the muscled appearance of the trunk and limbs.

The botanical name for the genus, Carpinus, is the original Latin name for the European species, although some etymologists derive it from the Celtic for a yoke.