| Piatra | |
| Name Other: | hu|Kőpatak, Pârâul Pietrei |
| Pushpin Map: | Romania |
| Subdivision Type1: | Country |
| Subdivision Name1: | Romania |
| Subdivision Type2: | Counties |
| Subdivision Name2: | Harghita County |
| Subdivision Type3: | Villages |
| Subdivision Name3: | Remetea |
| Length: | 8km (05miles) |
| Mouth: | Mureș |
| Mouth Location: | Remetea |
| Mouth Coordinates: | 46.794°N 25.4574°W |
| Basin Size: | 22km2 |
The Piatra (also: Pârâul Pietrei, hu|Kőpatak) is a left tributary of the river Mureș in Transylvania, Romania. It discharges into the Mureș in Remetea. Its length is 8km (05miles) and its basin size is 22km2. Its name means "Stone Creek" in both languages.