| Coordinates: | 50.6983°N 7.4956°W |
| Image Plan: | Fiersbach in AK.svg |
| State: | Rheinland-Pfalz |
| District: | Altenkirchen |
| Verbandsgemeinde: | Altenkirchen-Flammersfeld |
| Elevation: | 270 |
| Area: | 3.04 |
| Postal Code: | 57635 |
| Area Code: | 02686 |
| Licence: | AK |
| Gemeindeschlüssel: | 07 1 32 031 |
| Website: | www.fiersbach-ak.de |
| Mayor: | Carsten Pauly[1] |
| Leader Term: | 2019 - 24 |
Fiersbach is a municipality in the district of Altenkirchen, in Rhineland-Palatinate, Germany.