The Șumuleul Mare (also: Șomleul Mare; Hungarian: Nagy-Somlyó, pronounced[ˈnɒcʃomjoː]) is a small river in the Gurghiu Mountains, Harghita County, central Romania. It is a left tributary of the river Mureș.[1][2] It flows through the municipality Ciumani, and joins the Mureș near the village Ciumani. Its length is 17 km (11 mi) and its basin size is 54 km2 (21 sq mi).[2]