Lahaj; Lahij or Lahej (Arabic: ??? La?ij) is a city and an area located between Ta'izz and Aden in Yemen. From the 18th to the 20th century; its rulers were of the Al-Abdali family who with Al-Sallami; Al-Ramada; Al-Sindi and al-Aqrabi; claims relation to Ahl al-Bayt (the family of the Prophet Muhammad).

Lahij was the capital city of Sultanate of Lahej; a protectorate of the British Empire until 1967; when the sultan was expelled and the city became a part of People's Republic of South Yemen.