| Baj | |
| Other Name: | Wallern/Woj |
| Pushpin Map: | Hungary |
| Pushpin Map Caption: | Location of Baj in Hungary |
| Subdivision Type: | Country |
| Subdivision Name: | Hungary |
| Subdivision Type1: | Region |
| Subdivision Name1: | Komárom-Esztergom}} |
| Subdivision Type2: | County |
| Area Total Km2: | 21.13 |
| Area Footnotes: | [1] |
| Postal Code: | 2836 |
| Postal Code Type: | Postal code |
| Area Code: | +36 34 |
| Area Code Type: | Area code |
| Timezone: | CET |
| Utc Offset: | +1 |
| Timezone Dst: | CEST |
| Utc Offset Dst: | +2 |
| Total Type: | Total |
| Population Total: | 2870 |
| Population Density Km2: | auto |
| Population Density Urban Km2: | auto |
| Population Density Metro Km2: | auto |
| Population As Of: | 2012 |
| Population Footnotes: | [2] |
Baj (German: Wallern, Woj) is a village in Komárom-Esztergom county, Hungary.