| En Name: | Bychchagdan |
| Ru Name: | Быччагдан |
| Other Name: | Быччыгдаан |
| Other Lang: | Sakha |
| Coordinates: | 63.9°N 124°W |
| Map Label Position: | right |
| Federal Subject: | Sakha Republic |
| Adm District Jur: | Verkhnevilyuysky District |
| Adm Selsoviet Jur: | Dalyrsky Rural Okrug |
| Adm Selsoviet Type: | Rural okrug |
| Inhabloc Cat: | Rural locality |
| Inhabloc Type: | Selo |
| Mun District Jur: | Verkhnevilyuysky Municipal District |
| Mun District Jur Ref: | [1] |
| Rural Settlement Jur: | Dalyrsky Rural Settlement |
| Pop 2010Census: | 95 |
Bychchagdan (Russian: Быччагдан; Yakut: Быччыгдаан, Bıççıgdaan) is a rural locality (a selo) in Dalyrsky Rural Okrug of Verkhnevilyuysky District in the Sakha Republic, Russia, located 85km (53miles) from Verkhnevilyuysk, the administrative center of the district and 10km (10miles) from Dalyr, the administrative center of the rural okrug.[2] Its population as of the 2010 Census was 95,[3] of whom 54 were male and 41 female, down from 101 as recorded during the 2002 Census.[4]