| Mărtinia | |
| Pushpin Map: | Romania |
| Subdivision Type1: | Country |
| Subdivision Name1: | Romania |
| Subdivision Type2: | Counties |
| Subdivision Name2: | Alba County |
| Length: | 15km (09miles) |
| Mouth: | Sebeș |
| Mouth Location: | Mărtinie |
| Mouth Coordinates: | 45.7932°N 23.608°W |
| Basin Size: | 42km2 |
The Mărtinia[1] (also: Mărtinie) is a left tributary of the river Sebeș in Romania. It flows into the Sebeș in the village Mărtinie. Its length is 15km (09miles) and its basin size is 42km2.