| Trostianets | |
| Native Name: | Тростянець |
| Settlement Type: | Rural settlement |
| Pushpin Map: | Ukraine Vinnytsia Oblast#Ukraine |
| Coordinates: | 48.5167°N 43°W |
| Subdivision Type: | Country |
| Subdivision Type1: | Province |
| Subdivision Type2: | District |
| Established Title: | First mentioned |
| Established Date: | 1598 |
| Unit Pref: | Metric |
| Population Total: | 7257 |
| Population As Of: | 2022 |
| Population Density Km2: | auto |
| Timezone: | EET |
| Utc Offset: | +2 |
| Timezone Dst: | EEST |
| Utc Offset Dst: | +3 |
| Postal Code Type: | Postal code |
| Area Code Type: | Area code |
Trostianets (Ukrainian: Тростянець) is a rural settlement in Vinnytsia Oblast (province), Ukraine, located in the historic region of Podilia. It was formerly the administrative seat of Trostianets Raion, but is now administered within Haisyn Raion. The town is located on the Trostianets River, which is a tributary of the Southern Bug. The estimated population in 2022 was .
Trostianets was first mentioned in 1598. Historically, it was known as Adamhorod (Adamgrod), and was a private town in Poland, located in the Bracław Voivodeship, owned by the House of Potocki.
Until 26 January 2024, Trostianets was designated urban-type settlement. On this day, a new law entered into force which abolished this status, and Trostianets became a rural settlement.[1]