| Weißach | |
| Subdivision Type1: | Countries |
| Subdivision Name1: | Germany and Austria |
| Subdivision Type3: | Reference no. |
| Subdivision Name3: | DE: 2144, AT: 811144 |
| Length: | 33.5km (20.8miles) |
| Source1 Location: | On the |
| Source1 Elevation: | ca. |
| Mouth Location: | Between Langenegg and Doren into the Bregenzer Ach |
| Basin Size: | 216km2 |
| Tributaries Right: | Eibelebach |
| Tributaries Left: | Bolgenach |
| Custom Label: | References |
The Weißach is a 33.5adj=midNaNadj=mid, right-hand, eastern tributary of the Bregenzer Ach in the German and Austrian Alps. It forms a very short section of the Austria–Germany border, just south of the confluence with the Eibelebach.[1] It flows into the Bregenzer Ach near Doren.