| Official Name: | Open Door |
| Pushpin Map: | Argentina |
| Pushpin Label Position: | bottom |
| Pushpin Map Caption: | Location in Argentina |
| Pushpin Mapsize: | 200 |
| Pushpin Mapsize1: | 200 |
| Subdivision Type: | Country |
| Subdivision Type1: | Province |
| Subdivision Name1: | Buenos Aires |
| Subdivision Type2: | Partido |
| Subdivision Name2: | Luján |
| Population Total: | 5014 |
| Coordinates: | -34°N -63°W |
| Elevation M: | 27 |
| Postal Code Type: | CPA Base |
| Postal Code: | B 6708 |
| Area Code: | +54 2323 |
Open Door is a small town in Luján Partido, Buenos Aires Province, Argentina.
The settlement was founded in the early 20th century, and like many other settlements in Argentina the original nucleus of the settlement was a railway station. The settlement was originally called "Colonia Nacional Psiquiátrica Domingo Cabred", but the name was changed to Open Door, based upon Doctor Domingo Cabred's "open door" policy with regard to the treatment of the mentally ill.