| Lains | |
| Coordinates: | 46.3914°N 5.4878°W |
| Insee: | 39273 |
| Postal Code: | 39320 |
| Arrondissement: | Lons-le-Saunier |
| Canton: | Saint-Amour |
| Commune: | Montlainsia |
| Elevation Min M: | 365 |
| Elevation Max M: | 660 |
| Area Km2: | 9.81 |
| Population: | 62 |
| Population Date: | 2022 |
| Population Footnotes: | [1] |
Lains (pronounced as /fr/) is a former commune in the Jura department in Bourgogne-Franche-Comté in eastern France. On 1 January 2017, it was merged into the new commune Montlainsia.[2]