| Ulla River | |
| Map: | Rio Ulla watershed.png |
| Subdivision Type1: | Country |
| Subdivision Name1: | Spain |
| Subdivision Type2: | State |
| Subdivision Name2: | Galicia (Spain) |
| Length: | 132km (82miles) |
| Discharge1 Avg: | NaNlast1=Río Barja |
| Source1 Location: | Montes da Vacaloura, Monterroso, Province of Lugo |
| Source1 Coordinates: | 42.745, -7.82 |
| Source1 Elevation: | 570 m |
| Mouth: | Ría de Arousa estuary |
| Mouth Location: | near Catoira, Spain |
| Mouth Coordinates: | 42.67, -8.73 |
| Mouth Elevation: | sea level |
| Basin Size: | 2800km2 |
| Tributaries Left: | Arnego, Deza, Liñares, Vea, Valga, Louro |
| Tributaries Right: | Pambre, Furelos, Beseña, Iso, Lañas, Brandelos, Santa Lucía, Sar |
The Ulla (río Ulla in Galician and Spanish) is a river in Galicia, Spain.
Its source is sometimes given as Antas de Ulla and sometimes the neighbouring municipality of Monterroso. It flows to the Ría de Arosa estuary near the city of Catoira, Spain. Its basin is the largest in Galicia after the Minho River. Tributaries include the rivers Deza and Arnego.
The river is also valued by archaeologists owing to the large number of artifacts, dating as far back as the Neolithic, discovered here. The outlet of the Ulla River and the mouth of the estuary, called Ría de Arousa, are the two sites where archaeologists have discovered remains consistently. Rock carvings have been discovered here. The Ulla River is also important because it is the river in the northwest of the Iberian Peninsula to produce a large number of watery hoards, which were discovered in its lower reaches and its mouth.
According to E. Bascuas, "Ulla" is a form belonging to the old European hydronymy, and derived from the Indoeuropean root *wel- 'wheel, rotate'. This toponym is registered in 906 as "(fluvius) Volia", which had derived from a previous form *Wulia.[1]