| Diyun | |
| Native Name: | Dai Yun |
| Settlement Type: | Sub- District |
| Image Alt: | Dihing river and Mahabodhi society. |
| Pushpin Map: | India Arunachal Pradesh#India3 |
| Pushpin Label Position: | left |
| Pushpin Map Caption: | Location in Arunachal Pradesh, India |
| Coordinates: | 27.5451°N 96.0997°W |
| Subdivision Type: | Country |
| Subdivision Name: |  India |
| Subdivision Type1: | State |
| Subdivision Name1: | Arunachal Pradesh |
| Subdivision Type2: | District |
| Subdivision Name2: | Changlang |
| Established Date: | 1960s |
| Governing Body: | Arunachal Legislative Assembly |
| Unit Pref: | Metric |
| Area Total Km2: | 179 |
| Elevation M: | 205 |
| Population Total: | 32,007 |
| Population As Of: | 2011 |
| Population Density Km2: | 178.8 |
| Demographics Type1: | Languages |
| Demographics1 Title1: | Official |
| Demographics1 Info1: | English |
| Demographics1 Title2: | Spoken |
| Demographics1 Info2: | Chakma, Hindi |
| Timezone1: | IST |
| Utc Offset1: | +5:30 |
| Postal Code: | 792103 |
| Registration Plate: | AR |
| Official Name: | Diyun HQ. Block I & II |
| Blank Name Sec1: | Literacy |
| Blank Info Sec1: | 52.23% |
| Leader Title1: | MLA |
| Leader Name1: | Nikh Kamin |
Diyun is a small township or small city in the Changlang District of Arunachal Pradesh. It got its name from a very small seasonal river by the same name. It is surrounded by the foothills of the Eastern Himalayas on two sides and by the Patkai Bum Range on one side.[1] [2] [3] [4] [5] [6]