| Osieck | |
| Settlement Type: | Town |
| Subdivision Type: | Country |
| Subdivision Type1: | Voivodeship |
| Subdivision Name1: | Masovian |
| Subdivision Type2: | County |
| Subdivision Name2: | Otwock |
| Subdivision Type3: | Gmina |
| Subdivision Name3: | Osieck |
| Coordinates: | 51.9667°N 46°W |
| Pushpin Map: | Poland |
| Pushpin Label Position: | bottom |
| Population Total: | 920 |
| Timezone: | CET |
| Utc Offset: | +1 |
| Timezone Dst: | CEST |
| Utc Offset Dst: | +2 |
| Registration Plate: | WOT |
Osieck is a town in Otwock County, Masovian Voivodeship, in east-central Poland. It is the seat of the gmina (administrative district) called Gmina Osieck.[1] It lies approximately 20km (10miles) south-east of Otwock and 400NaN0 south-east of Warsaw.
On 4 June 1981, a collision between two trains occurred near Osieck, killing 25 people.
Osieck was deprived of its town rights by the Tsar on June 1, 1869, which was a way to punish the city for the participation of its inhabitants in the January Uprising. On 1 January 2024 after 155 years Osieck regained its town rights.[2]