| Name | Jämsä |
| Office head of government | |
| Mayor | |
| Image |  |
| Area (m²) | 1,004,000,000 |
| Date founded | 1866 |
| Elevation (m) | |
| Country | Finland |
| Administrative division | Central Finland |
| Continent | Europe |
| Latitude (°) | 61.8666648865 |
| Waterbody | Lake päijänne |
| Longitude (°) | 25.1833324432 |
| Website | http://www.jamsa.fi/ |
| Population (people) | 20,877 (31/12/2017) |
| Demonym |