| Image Coa: | Wappen Untermerzbach W.svg |
| Coordinates: | 50.1294°N 10.86°W |
| Image Plan: | Untermerzbach in HAS.svg |
| State: | Bayern |
| Region: | Unterfranken |
| District: | Haßberge |
| Elevation: | 264 |
| Area: | 27.75 |
| Postal Code: | 96190 |
| Area Code: | 09533 |
| Licence: | HAS |
| Gemeindeschlüssel: | 09 6 74 210 |
| Website: | www.untermerzbach.de |
| Mayor: | Helmut Dietz[1] |
| Leader Term: | 2020 - 26 |
| Party: | SPD |
Untermerzbach is a municipality in the district of Haßberge in Bavaria in Germany.