| Ostrov | |
| Settlement Type: | Municipality |
| Subdivision Type: | Country |
| Subdivision Name: | Slovakia |
| Subdivision Type2: | Region |
| Subdivision Name2: | Trnava |
| Subdivision Type3: | District |
| Subdivision Name3: | Piešťany |
| Pushpin Map: | Slovakia Trnava Region#Slovakia |
| Pushpin Relief: | 1 |
| Pushpin Map Caption: | Location of Ostrov in the Trnava Region |
| Pushpin Label Position: | bottom |
| Coordinates: | 48.6292°N 17.7658°W |
| Established Title: | First mentioned |
| Established Date: | 1431 |
| Area Total Km2: | 9.35[1] |
| Area Total Sq Mi: | 3.61 |
| Elevation M: | 163[2] |
| Elevation Ft: | 535 |
| Population Total: | 1204[3] |
| Population Density Km2: | 128.66[4] |
| Population Density Sq Mi: | 49.68 |
| Postal Code Type: | Postal code |
| Postal Code: | 922 01 |
| Area Code: | +421 33 |
| Blank Name: | Car plate |
| Blank Info: | PN |
| Website: | www.obecostrov.sk |
Ostrov (Hungarian: Osztró) is a village and municipality in Piešťany District in the Trnava Region of western Slovakia.
In historical records the village was first mentioned in 1431.
The municipality lies at an altitude of 166 metres and covers an area of 9.358 km2. It has a population of about 1154 people.
'Ostrov' is the Slovak word for island.