| Mul-Baiyer District | |
| Pushpin Map: | Papua New Guinea |
| Coordinates: | -5.55°N 191°W |
| Pushpin Label Position: | right |
| Pushpin Map Caption: | Location within Papua New Guinea |
| Subdivision Type: | Country |
| Subdivision Name: | Papua New Guinea |
| Subdivision Type1: | Province |
| Subdivision Name1: | Western Highlands Province |
| Seat Type: | Capital |
| Seat: | Baiyer |
| Area Total Km2: | 1376 |
| Population Total: | 83036 |
| Population As Of: | 2011 census |
| Population Density Km2: | auto |
| Demographics1 Title1: | Main languages |
| Timezone1: | AEST |
| Utc Offset1: | +10 |
Mul-Baiyer District is a district of the Western Highlands Province of Papua New Guinea. Its capital is Baiyer. The population of the district was 83,036 at the 2011 census.[1]