| Sanamxai | |
| Settlement Type: | Town |
| Pushpin Map: | Laos |
| Pushpin Label Position: | right |
| Pushpin Map Caption: | Location in Laos |
| Subdivision Type: | Country |
| Subdivision Name: | Laos |
| Subdivision Type1: | Province |
| Subdivision Name1: | Attapeu Province |
| Subdivision Type2: | District |
| Subdivision Name2: | Sanamxay District |
| Timezone: | ICT |
| Utc Offset: | +7 |
| Coordinates: | 14.6825°N 106.5828°W |
Sanamxai, Sanamxay, or Muang Sanamxai is a small river town on the Xe Khong River in Attapeu Province, in southern Laos.[1] It is the capital of Sanamxay District. It is downriver from the provincial capital of Attapeu and is connected by Lao National Highway 18.