Suopiai is a village in Šakiai District Municipality, in Marijampolė County, Lithuania. Suopiai lies at 58 m above sea level. The nearest city is Kaunas, 40 km to the east. Among the landmarks around are Ninth Fort (39 km), M. K. Čiurlionis National Art Museum (42 km) and Panemunė Castle (25 km).