| Type: | commune |
| County: | Tulcea |
| Population Total: | auto |
| Subdivisions: | Ostrov, Piatra |
| Ostrov | |
| Coordinates: | 44.9333°N 37°W |
| Area Total Km2: | 118.796 |
| Leader Name: | Ion Tănase[1] |
| Leader Term: | 2020 - 2024 |
| Leader Party: | PSD |
| Postal Code: | 827175 |
Ostrov is a commune in Tulcea County, Northern Dobruja, Romania. It is composed of two villages, Ostrov and Piatra.
It is the site of the Roman fort Beroe in the Roman province of Moesia and part of the defensive frontier system of the Limes Moesiae along the Danube.[2]
The Beroe archaeological site is on the bank of the branch of the Danube River, 3 km south of Ostrov village. The first historical reference related to the fortress dates to the 2 century AD, the fort being inhabited until the early 7 century.