| Thyra | |
| Subdivision Type1: | Country |
| Subdivision Name1: | Germany |
| Subdivision Type2: | State |
| Subdivision Name2: | Saxony-Anhalt |
| Subdivision Type3: | District |
| Subdivision Name3: | Mansfeld-Südharz |
| Length: | 20km (10miles) |
| Source1 Location: | in Stolberg |
| Mouth Location: | in the Helme |
| Basin Landmarks: | Villages: Südharz, Berga |
| Discharge1 Location: | at Stolberg gauge |
| Discharge1 Min: | Record low: [1] (in 2003) Average low: |
| Discharge1 Max: | Average high: Record high: (in 1955) |
| Bridges: | Thyra Viaduct |
| Custom Label: | Navigable |
| Custom Data: | no |
The Thyra is a 20adj=midNaNadj=mid river of Saxony-Anhalt, Germany, in the district of Mansfeld-Südharz in the Harz Mountains.
The Thyra begins its course in the old quarter of Stolberg in the Harz Mountains at the confluence of three mountain streams - the Große Wilde, Kleine Wilde and Lude[2] - and then flows through Stolberg, where several streams join it, before heading south through a steep valley to Rottleberode. Here the Thyra valley becomes very wide, but near Uftrungen it narrows again. South of Uftrungen the Thyra leaves the Harz and enters the Goldene Aue, crossing and Berga, before this little river enters the Helme.
Several things are named after the Thyra, for example the Thyra thermal baths (Thyratherme) in Stolberg or the railway line known as the Thyraliesel.