Lupiac () is a commune in the Gers department in southwestern France.
The Auzoue forms most of the commune's southeastern border. The Douze forms the commune's western border.
Charles de Batz de Castelmore d'Artagnan ( 1611 â 25 June 1673), a captain of the Musketeers of the Guard, was born here. A fictionalized version of his life is central to The Three Musketeers by Alexandre Dumas, père. Lupiac has a museum dedicated to him.