Loudun (/luːˈdʌn/; French pronunciation:[lu.dœ̃]) is a commune in the Vienne department in the Poitou-Charentes region in western France.
It is located 30km (19mi) south of the town of Chinon and 25km to the east of the town Thouars. The area south of Loudun is the place of origin of a significant portion of the Acadians, one of the early founding people of New France in Canada.