| En Name: | Spas-Demensky District |
| Ru Name: | Спас-Деменский район |
| Coordinates: | 54.4167°N 36°W |
| Image View: | С. Лазинки. Братская могила.jpg |
| Image Coa: | Coat of Arms of Spas-Demensk (Kaluga oblast) (2008).png |
| Federal Subject: | Kaluga Oblast |
| Adm Data As Of: | 2017 |
| Adm Ctr Type: | town |
| Adm Ctr Name: | Spas-Demensk |
| No Of Cities Towns: | 1 |
| No Of Rural Localities: | 128 |
| Mun Data As Of: | February 2015 |
| Mun Formation1: | Spas-Demensky Municipal District |
| Mun Formation1 No Of Urban Settlements: | 1 |
| Mun Formation1 No Of Rural Settlements: | 12 |
| Area Km2: | 1369 |
| Pop 2010Census: | 8238 |
| Urban Pop 2010Census: | 59.4% |
| Rural Pop 2010Census: | 40.6% |
| Established Date: | 1929 |
| Website: | http://www.admspasdem.ru |
| Date: | November 2017 |
| Population of Spas-Demensky District | |
| Label1: | 2021 Census |
| Data1: | 7,469 |
| Label2: | 2010 Census |
| Data2: | 8,238 |
| Label3: | 2002 Census |
| Data3: | 10,017 |
| Label4: | 1989 Census |
| Data4: | 13,058 |
| Label5: | 1979 Census |
| Data5: | 27,533 |
Spas-Demensky District (Russian: Спас-Де́менский райо́н) is an administrative[1] and municipal[2] district (raion), one of the twenty-four in Kaluga Oblast, Russia. It is located in the west of the oblast. The area of the district is 1369km2.[3] Its administrative center is the town of Spas-Demensk. As of the 2021 Census, the total population of the district was 7,369, with the population of Spas-Demensk accounting for 62.0% of that number.
The district was established in 1929 within Sukhinichi Okrug of Western Oblast from a part of former Mosalsky Uyezd.[4] It became a part of Kaluga Oblast on July 5, 1944.