| Ruukki | |
| Official Name: | Finnish: Ruukin kunta Swedish: Ruukki kommun |
| Settlement Type: | Former municipality |
| Mapsize: | 150px |
| Subdivision Type: | Country |
| Subdivision Name: | Finland |
| Subdivision Type1: | Region |
| Subdivision Name1: | Northern Ostrobothnia |
| Established Title: | Charter |
| Established Date: | 1973 |
| Extinct Title: | Consolidated |
| Extinct Date: | 2007 |
| Area Footnotes: | [1] |
| Area Total Km2: | 772.58 |
| Area Land Km2: | 766.79 |
| Area Water Km2: | 5.79 |
| Population As Of: | 2006-12-31 |
| Population Footnotes: | [2] |
| Population Total: | 4505 |
| Population Density Km2: | auto |
| Timezone: | EET |
| Utc Offset: | +2 |
| Timezone Dst: | EEST |
| Utc Offset Dst: | +3 |
| Coordinates: | 64.6639°N 25.1014°W |
Ruukki is a former municipality of Finland.
It is located in the province of Oulu and is part of the Northern Ostrobothnia region. The municipality had a population of 4,505 (31 December 2006) and covered an area of of which 5.79km2 is water. The population density was .
The municipality was unilingually Finnish.
In 2007 municipality of Ruukki joined together with Siikajoki.