| Sędeń Duży | |
| Settlement Type: | Village |
| Total Type: | |
| Subdivision Type: | Country |
| Subdivision Type1: | Voivodeship |
| Subdivision Name1: | Masovian |
| Subdivision Type2: | County |
| Subdivision Name2: | Płock |
| Subdivision Type3: | Gmina |
| Subdivision Name3: | Łąck |
| Pushpin Map: | Poland |
| Coordinates: | 52.4989°N 19.5697°W |
| Population Total: | 320 |
Sędeń Duży is a village in the administrative district of Gmina Łąck, within Płock County, Masovian Voivodeship, in east-central Poland.[1] It lies approximately 5km (03miles) north-west of Łąck, 110NaN0 south-west of Płock, and 1030NaN0 west of Warsaw.