| Lago di Cei | |
| Location: | Trentino |
| Pushpin Map: | Italy |
| Coords: | 45.951°N 11.02°W |
| Outflow: | Rio Arione |
| Basin Countries: | Italy |
| Depth: | 13.5m (44.3feet) |
| Elevation: | 918m (3,012feet) |
| Islands: | 1 little island |
| Cities: | Castellano, frazione of Villa Lagarina |
Lago di Cei (Lach de Zéi in local dialect), is a lake in the comune of Villa Lagarina, not far from Rovereto in Trentino, northern Italy.
The whole basin in which the lake lies was once occupied by a single, larger lake. After the latter drained, two smaller lakes remained: the largest, having a surface of c. 4.5 hectares, receives the water of the other (called Lagabis), which has a semicircular shape a from which the Rio Arione outflows.