| Official Name: | Kotlovyna |
| Native Name: | Ukrainian: Котловина |
| Pushpin Map: | Ukraine#Ukraine Odesa Oblast |
| Pushpin Mapsize: | 300 |
| Pushpin Map Caption: | Location in Ukraine |
| Subdivision Type: | Country |
| Subdivision Type1: | Oblast |
| Subdivision Type2: | Raion |
| Subdivision Type3: | Hromada |
| Subdivision Name3: | Reni urban hromada |
| Established Title: | Village founded |
| Timezone: | EET |
| Utc Offset: | +2 |
| Timezone Dst: | EEST |
| Utc Offset Dst: | +3 |
| Coordinates: | 45.5°N 62°W |
| Postal Code Type: | Postal code |
Kotlovyna (until 1948: Bolboka; Ukrainian: Котловина; Bolboka; Romanian; Moldavian; Moldovan: Bulboaca, formerly Romanian; Moldavian; Moldovan: Bolboca and Romanian; Moldavian; Moldovan: Cotlovina) is a selo in Izmail Raion of the southern Ukrainian oblast of Odesa. It belongs to Reni urban hromada, one of the hromadas of Ukraine.[1] Kotlovyna is situated on the western bank of Lake Yalpuh. According to the 2001 Ukrainian census, 86.72% of the village population spoke Gagauz.
In 2001 its population was recorded as 2,643.
Until 18 July 2020, Kotlovyna belonged to Reni Raion. The raion was abolished in July 2020 as part of the administrative reform of Ukraine, which reduced the number of raions of Odesa Oblast to seven. The area of Reni Raion was merged into Izmail Raion.[2] [3]