| Official Name: | Kastelec |
| Other Name: | Castel |
| Pushpin Map: | Slovenia |
| Pushpin Label Position: | bottom |
| Pushpin Map Caption: | Location in Slovenia |
| Coordinates: | 45.5813°N 13.8717°W |
| Subdivision Type: | Country |
| Subdivision Name: |  Slovenia |
| Subdivision Type1: | Traditional region |
| Subdivision Name1: | Littoral |
| Subdivision Type2: | Statistical region |
| Subdivision Name2: | Coastal–Karst |
| Subdivision Type3: | Municipality |
| Subdivision Name3: | Koper |
| Area Total Km2: | 3.75 |
| Elevation M: | 317.3 |
| Population Total: | 46 |
| Population As Of: | 2002 |
| Footnotes: | [1] |
Kastelec (pronounced as /sl/, it|Castel) is a settlement in the City Municipality of Koper in the Littoral region of Slovenia.[2]
The local church is dedicated to the Exaltation of the Holy Cross and belongs to the Parish of Klanec.[3]