| Tamnagar | |
| Native Name: | तामनगर |
| Settlement Type: | subdivision of Butwal Municipality |
| Motto: | 27°41'04.7"N 83°23'49.9"E |
| Mapsize: | 300px |
| Pushpin Label Position: | bottom |
| Pushpin Mapsize: | 360 |
| Pushpin Map Caption: | Location in Nepal |
| Subdivision Type: | Country |
| Subdivision Name: |  Nepal |
| Subdivision Type1: | Province |
| Subdivision Name1: | Lumbini Province |
| Subdivision Type2: | District |
| Subdivision Name2: | Rupandehi District |
| Population As Of: | 1991 |
| Population Total: | 5786 |
| Population Density Km2: | auto |
| Population Blank1 Title: | Ethnicities |
| Timezone: | Nepal Time |
| Utc Offset: | +5:45 |
Tamnagar is a former Village Development Committee (VDC) and now part of Butwal Sub-Metropolitan municipality in Rupandehi District in Lumbini Province of southern Nepal. At the time of the 1991 Nepal census it had a population of 5786 people living in 1129 individual households.[1]