| Municipality of Kostel | |
| Native Name: | Občina Kostel |
| Native Name Lang: | sl |
| Settlement Type: | Municipality |
| Coordinates: | 45.5088°N 14.91°W |
| Subdivision Type: | Country |
| Subdivision Name: |  Slovenia |
| Leader Title: | Mayor |
| Leader Name: | Ivan Črnkovič |
| Unit Pref: | Metric |
| Area Total Km2: | 56.09 |
| Population Total: | 637 |
| Population As Of: | 2018 |
| Population Density Km2: | auto |
| Timezone1: | CET |
| Utc Offset1: | +01 |
| Timezone1 Dst: | CEST |
| Utc Offset1 Dst: | +02 |
| Postal Code: | 1336 |
The Municipality of Kostel (pronounced as /sl/; sl|Občina Kostel) is a municipality in southern Slovenia. Its seat is the settlement of Vas.[1] It is part of the traditional region of Lower Carniola and is now included in the Southeast Slovenia Statistical Region.[2] It borders Croatia.
In addition to the municipal seat of Vas, the municipality also includes the following settlements: