| Oulujoki | |
| Name Other: | Ule älv |
| Subdivision Type1: | Country |
| Subdivision Name1: | Finland |
| Length: | 107km (66miles) |
| Discharge1 Avg: | 250m3/s |
| Source1: | Oulujärvi |
| Source1 Location: | Vaala, Finland |
| Source1 Coordinates: | 64.55°N 76°W |
| Source1 Elevation: | 122m (400feet) |
| Mouth: | Bothnian Bay |
| Mouth Location: | Oulu, Finland |
| Mouth Coordinates: | 65.0167°N 52°W |
| Mouth Elevation: | 0m (00feet) |
| Basin Size: | 22900km2 |
| Tributaries Left: | Muhosjoki |
| Tributaries Right: | Sanginjoki, Utosjoki, Kutujoki |
Oulujoki (Swedish: Ule älv) is a river in Oulu province, Finland. Its name in Finnish means literally "Oulu River", originally in old Northern Ostrobothnian dialect literally "Flood River". Its origin is Oulujärvi and its watershed area covers a significant part of Kainuu region. It flows into the Bothnian Bay at Oulu. Port of Oulu is located at the mouth of the river.