| Guadiela | |
| Source1 Location: | Fuente Pinilla |
| Mouth: | Tagus |
| Mouth Coordinates: | 40.3625°N -2.8162°W |
| Subdivision Type1: | Country |
| Subdivision Name1: | Spain |
| Subdivision Type2: | Region |
| Subdivision Name2: | Castilla–La Mancha |
| Length: | 117km (73miles) |
| Extra: | Tagus Basin |
The Guadiela is a river in the Iberian Peninsula, a left-bank tributary of the Tagus and the latter's major upper-course tributary.[1]
The Guadiela has its source in the, near Cueva del Hierro,[2] at the Fuente Pinilla site.[3] It flows from East to West for 117km (73miles), passing through the Spanish province of Cuenca, emptying into the Tagus at the Bolarque reservoir,[4] on the border between the provinces of Cuenca and Guadalajara. It is dammed upstream by the .
It receives the waters from the,, and .[5]
The hydronym Guadiela is formed by 'Guad' (of Arabic origin, conveying the meaning of "river") and the '-iela' suffix (a diminutive).[6]