| Alcoa | |
| Mouth: | Atlantic Ocean |
| Mouth Location: | Nazaré |
| Mouth Coordinates: | 39.5803°N -9.0847°W |
| Pushpin Map: | Portugal |
| Subdivision Type1: | Country |
| Subdivision Name1: | Portugal |
| Tributaries Left: | Baça |
The Alcoa (pronounced as /pt/) is a river of Portugal, flowing into the Atlantic Ocean.[1] It rises in the municipality of Alcobaça and flows into the ocean near Nazaré. The river section below the confluence with its tributary Baça is also referred to as Alcobaça.