| Name other | Nagy-Somlyó |
|---|---|
| Country | Romania |
| Counties | Harghita County |
| Villages | Ciumani |
| Source 1 | Gurghiu Mountains, Mount Opro |
| Source1 coordinates | 46°35′18″N 25°25′45″E |
| Source1 elevation | 1,349 m (4,426 ft) |
| Mouth | Mureș |
| Mouth location | Ciumani |
| Mouth coordinates | 46°41′15″N 25°29′25″E |
| Mouth elevation | 733 m (2,405 ft) |
| Tributaries right | Șumuleul Mic |
The Șumuleul Mare (also: Șomleul Mare; Hungarian: Nagy-Somlyó, ˈnɒcʃomjoː) is a small river in the Gurghiu Mountains, Harghita County, central Romania. It is a left tributary of the river Mureș. 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).