| Municipality of Hrastnik | |
| Native Name: | Občina Hrastnik |
| Native Name Lang: | sl |
| Settlement Type: | Municipality |
| Coordinates: | 46.1333°N 21°W |
| Subdivision Type: | Country |
| Subdivision Name: |  Slovenia |
| Leader Title: | Mayor |
| Leader Name: | Marko Funkl |
| Unit Pref: | Metric |
| Area Total Km2: | 58.6 |
| Population Footnotes: | [1] |
| Population Total: | 10121 |
| Population As Of: | 2002 |
| Population Density Km2: | auto |
| Timezone1: | CET |
| Utc Offset1: | +01 |
| Timezone1 Dst: | CEST |
| Utc Offset1 Dst: | +02 |
The Municipality of Hrastnik (pronounced as /sl/; sl|Občina Hrastnik) is a municipality in central Slovenia. The seat of the municipality is the town of Hrastnik. The area is part of the traditional Styria region. The entire municipality is now included in the Central Sava Statistical Region.
Located in the valley of a minor left bank tributary of the Sava River, the area is known for its rich deposits of coal. Coal mining began in the area in 1804. Surrounding peaks include Mount Kum (1220 m), Mount Mrzlica (1122 m), and Kopitnik Hill (910 m). The area around Kopitnik is protected as a nature reserve. Species such as the capercaillie and chamois run wild in the surrounding forests.[2]
In addition to the municipal seat of Hrastnik, the municipality also includes the following settlements: