| Séd | |
| Subdivision Type1: | Country |
| Subdivision Name1: | Hungary |
| Mouth Location: | Sárvíz |
| Mouth Coordinates: | 47.1517°N 18.3494°W |
| Progression: | Sárvíz→ |
| Length: | 70km (40miles) |
Séd is a river in western Hungary, north of Lake Balaton. It is long and flows through the city of Veszprém. It starts in the Bakony region and is a tributary to the Sárvíz near Cece.[1]
The river once had many watermills along its length. The first recorded water wheel on the Séd was donated by Gisela of Hungary to Bakonybél Abbey in 1037.