| Official Name: | Holtsås |
| Other Name: | Holtsaas (historic) |
| Settlement Type: | Village |
| Pushpin Map: | Telemark#Norway |
| Pushpin Label Position: | top |
| Pushpin Map Caption: | Location of the village |
| Subdivision Type: | Country |
| Subdivision Name: | Norway |
| Subdivision Name1: | Eastern Norway |
| Subdivision Name2: | Telemark |
| Subdivision Type3: | District |
| Subdivision Name3: | Aust-Telemark |
| Subdivision Type4: | Municipality |
| Subdivision Name4: | Midt-Telemark Municipality |
| Utc Offset1: | +01:00 |
| Utc Offset1 Dst: | +02:00 |
| Postal Code Type: | Post Code |
| Postal Code: | 3683 Notodden |
| Coordinates: | 59.4568°N 9.3394°W |
| Elevation M: | 128 |
| Elevation Footnotes: | [1] |
Holtsås is a village in Midt-Telemark Municipality in Telemark county, Norway. The village is located near the south end of the lake Heddalsvatnet, about south of the village of Hjuksebø (in Notodden Municipality) and about north of the village of Nordagutu.
Holtsås used to have a train station on the Sørlandet Line. The Hjuksebø train disaster occurred between Hjuksebø and Holtsås on 15 November 1950, and was Norway's worst railway accident in peacetime until the Tretten train disaster in 1975.