| Official Name: | Yuldybay |
| Native Name: | Юлдыбай |
| Native Name Lang: | ru |
| Settlement Type: | Village |
| Pushpin Map: | Russia Bashkortostan#Russia |
| Subdivision Type: | Country |
| Subdivision Name: | Russia |
| Subdivision Type1: | Region |
| Subdivision Name1: | Bashkortostan |
| Subdivision Type2: | County |
| Subdivision Type3: | District |
| Subdivision Name3: | Kugarchinsky District |
| Subdivision Type4: | Municipality |
| Utc Offset1: | +5:00 |
| Coordinates: | 52.6333°N 102°W[1] |
Yuldybay (Russian: Юлдыбай; Bashkir: Юлдыбай, Yuldıbay) is a rural locality (a village) and the administrative centre of Yuldybayevsky Selsoviet, Kugarchinsky District, Bashkortostan, Russia. The population was 276 as of 2010.[2] There are 6 streets.
Yuldybay is located 15 km southeast of Mrakovo (the district's administrative centre) by road. Novokhvalynsky is the nearest rural locality.[3]