| Topsæ | |
| Pushpin Map: | Agder#Norway |
| Pushpin Label Position: | bottom |
| Pushpin Map Caption: | Location of the lake |
| Coordinates: | 58.9792°N 7.882°W |
| Location: | Bygland, Agder |
| Inflow: | Kjætebuvatnet |
| Outflow: | Storåna river |
| Catchment: | Tovdalselva watershed |
| Basin Countries: | Norway |
| Area: | 2.4km2 |
| Reference: | NVE |
Topsæ is a lake in the municipality of Bygland in Agder county, Norway. The 2.4km2 lake is located east of the lake Hovatn, about northeast of the village of Åraksbø. The Topsæfossen waterfall is located at the north end of the lake at the primary inflow. At the southeastern corner of the lake, there is a small dam to regulate the outflow of the lake into the Tovdalselva watershed.[1]