| Gleierbach | |
| Mouth Location: | Lenne |
| Mouth Coordinates: | 51.1641°N 8.3123°W |
| Subdivision Type1: | Country |
| Length Km: | 7.1 |
Gleierbach (also: Gleiderbach, in its upper and middle course also Westernah or Westernahbach) is a river of North Rhine-Westphalia, Germany. It flows through the municipality Schmallenberg. It is a right tributary of the Lenne, which it joins in Gleidorf, east of Schmallenberg.