| Willi Haag | |
| Birth Date: | 1944 8, df=yes |
| Birth Place: | Sohren, Germany |
| Position: | defender |
| Years1: | 1963–1967 |
| Clubs1: | SV Eintracht Trier 05 |
| Years2: | 1967–1970 |
| Clubs2: | Bayer 04 Leverkusen |
| Years3: | 1970–1972 |
| Clubs3: | Preußen Münster |
| Years4: | 1972–1975 |
| Clubs4: | Alemannia Aachen |
| Manageryears1: | 1977–1978 |
| Managerclubs1: | Alemannia Aachen (assistant) |
| Manageryears2: | 1978 |
| Managerclubs2: | Alemannia Aachen |
| Manageryears3: | 1978–1986 |
| Managerclubs3: | Alemannia Aachen (assistant) |
Willi Haag (born 6 August 1944) is a retired German football defender and later manager.