knee-length skirtlike garment that is worn by men as a major element of the traditional national garb of Scotland. (The other main component of Highland dress, as the traditional male garb of Scotland is called, is the plaid, which is a rectangular length of cloth worn over the left shoulder.) The kilt is a length of woven wool that is permanently pleated except for sections at each end and wrapped around the wearer's waist in such a way that the pleats are massed at the wearer's back and the flat, unpleated ends overlap to form a double layer at his front. Both kilt and plaid are usually made of cloth woven with a cross-checked repeating pattern known as a tartan (q.v.).

The kilt and plaid ensemble developed in 17th-century Scotland from the féile-breacan, a long piece of woolen cloth whose pleated first half was wrapped around the wearer's waist, while the (unpleated) second half was then wrapped around the upper body, with a loose end thrown over the left shoulder. Subsequently in the 17th century two lengths of cloth began to be worn for these purposes, and the kilt and plaid thus came to be separate garments.

The plaid and kilt form the only national costume in the British Isles that is worn for ordinary purposes, rather than merely for special occasions. Highland dress is also the uniform of Scottish regiments in the British army, and kilts have been worn in battle as recently as World War II.