Tisleifjorden is a lake on the border of Innlandet and Buskerud counties in Norway. The lake lies in Nord-Aurdal Municipality in Innlandet county, as well in Gol Municipality and Hemsedal Municipality in Buskerud county. Tisleifjorden is dammed for hydroelectric power. The elevation of the lake lies around 819 metres (2,687 ft) above sea level, but it can vary up to 11 metres (36 ft). The 13.54-square-kilometre (5.23 sq mi) lake has a circumference of about 32.5 kilometres (20.2 mi). It is located about 25 kilometres (16 mi) to the southwest of the town of Fagernes.

The Tisleifjorden Dam creates a reservoir for the Åbjøra kraftverk hydro-electric power plant along the Aurdalsfjorden near the village of Aurdal. The power plant was built from 1949-1951 and it was rebuilt in 2002. Åbjøra kraftverk is operated by Skagerak Energi.