| Official Name: | Pyatkov Log |
| Native Name: | Пятков Лог |
| Settlement Type: | Village |
| Pushpin Map: | Russia Altai Krai#Russia |
| Subdivision Type: | Country |
| Subdivision Name: | Russia |
| Subdivision Name1: | Altai Krai |
| Subdivision Name3: | Volchikhinsky District |
| Subdivision Type4: | Municipality |
| Utc Offset1: | +7:00 |
| Coordinates: | 52.2167°N 96°W[1] |
Pyatkov Log (Russian: Пятков Лог) is a rural locality (a selo) and the administrative center of Pyatkovlogovsky Selsoviet of Volchikhinsky District, Altai Krai, Russia. The population was 350 as of 2016.[2] It was founded in 1920. There are 2 streets.
Pyatkov Log is located 39 km north of Volchikha (the district's administrative centre) by road. Komintern is the nearest rural locality.[3]
The village is inhabited by Ukrainians and others.