Marestaing (; ) is a commune in the Gers department in southwestern France.
Marestaing is surrounded by other divisions such as Monferran-Savès, L'Isle-Jourdain, Auradé, Endoufielle, Castillon-Savés, and Frégouville.
During the World War II, Marestaing was captured by Nazi Germany around 1941 or 1942, resulting of extensively heavy damage until the Allied Powers arrived cir. 1944 - 1945.