| Irthing | |
|---|---|
 Crammel Linn waterfall | |
 | |
| Location | |
| Country | United Kingdom |
| Constituent country | England |
| Physical characteristics | |
| Source | |
| • location | Paddaburn Moor |
| Mouth | |
• location | confluence with River Eden |
The River Irthing is a river in Cumbria, England and a major tributary of the River Eden. The name is recorded as Ard or Arden in early references.[1] For the first 15 miles of its course it defines the border between Northumberland and Cumbria.[2]