| Strei | |
| Name Other: | Sztrigy, Râul Petros |
| Map: | Raul Strei.png |
| Subdivision Type1: | Country |
| Subdivision Name1: | Romania |
| Subdivision Type2: | Counties |
| Subdivision Name2: | Hunedoara County |
| Subdivision Type3: | Towns |
| Subdivision Name3: | Călan |
| Length: | 93km (58miles) |
| Source1: | Mount Bătrâna |
| Source1 Location: | Șureanu Mountains |
| Mouth: | Mureș |
| Mouth Location: | near Simeria |
| Mouth Coordinates: | 45.8514°N 23.0507°W |
| Basin Size: | 1983km2 |
| Tributaries Left: | Bărbat, Râul Mare |
| Tributaries Right: | Valea Luncanilor |
The Strei (Hungarian: Sztrigy) is a left tributary of the river Mureș in Transylvania, Romania. The upper reach of the river, upstream of the village of Baru, is also known as Râul Petros. It flows through the town Călan and the villages Petros, Baru, Livadia, Pui, Galați, Băiești, Ohaba de sub Piatră, Ciopeia, Subcetate, Covragiu, Bretea Română, Bretea Streiului, Ruși, Strei, Streisângeorgiu, Batiz, Băcia and Simeria Veche. It discharges into the Mureș near Simeria.[1] Its length is 93km (58miles) and its basin size is 1983km2.
The following rivers are tributaries to the river Strei (from source to mouth):