| Official Name: | Ereño |
| Pushpin Map: | Spain Basque Country#Spain |
| Pushpin Map Caption: | Location of Ereño within the Basque Country##Location of Ereño within Spain |
| Coordinates: | 43.3511°N -2.6158°W |
| Subdivision Type: | Country |
| Subdivision Name: |  Spain |
| Subdivision Type1: | Autonomous community |
| Subdivision Type2: | Province |
| Subdivision Name2: | Biscay |
| Subdivision Type3: | Comarca |
| Subdivision Name3: | Busturialdea |
| Leader Title: | Mayor |
| Leader Name: | Joseba Zarragoikoetxea Zenicacelaya |
| Area Total Km2: | 10.67 |
| Elevation M: | 278 |
| Population Density Km2: | auto |
| Timezone: | CET |
| Utc Offset: | +1 |
| Timezone Dst: | CEST |
| Utc Offset Dst: | +2 |
| Postal Code Type: | Postal code |
| Postal Code: | 48313 |
| Website: | www.ereno.org |
Ereño is a town and municipality located in the province of Biscay, in the autonomous community of the Basque Country, northern Spain.
Ereño is famous for its marble. In the 1st century CE the Romans were mining the quarries, which are no longer being used. There are literary references that call Ereño the "capital of the marble route". This material can be found in numerous buildings in Urdaibai and also on the other side of the ocean.
According to historian Tomás de Goikolea, Ereño was built in the 9th century and the residents of the town may be direct descendants of the inhabitants of the Santimamiñe cave.
On 29 September, the San Miguel festival, a popular mass is held and a pilgrimage is done.