| Longeau | |
| Settlement Type: | Village |
| Pushpin Map: | Belgium |
| Pushpin Map Caption: | Location in Belgium |
| Population Total: | 673 |
| Utc Offset: | +1 |
| Coordinates: | 49.5786°N 5.8333°W |
| Postal Code: | 6780 |
Longeau (Luxembourgish; Letzeburgesch: Laser) is a village of Wallonia in the municipality and district of Messancy, located in the province of Luxembourg, Belgium.