Lannemezan (French pronunciation: ​[lanməzɑ̃]; Gascon Occitan Lanamesa, "heath of the middle") is a commune in the Hautes-Pyrénées department and the Midi-Pyrénées region in south-western France. The inhabitants are called Lannemezanais.

Since 24 December 2003, Lannemezan has belonged to the Communauté de communes du Plateau de Lannemezan, which it was the main town. Since 1 January 2014, it belongs to the Communauté de communes du Plateau de Lannemezan et des Baïses, of which it is still the largest city.