Systrafoss ('sisters' waterfall') is a waterfall in Iceland, found at Kirkjubæjarklaustur in Skaftárhreppur in Suðurland area.
The waterfall is part of the river Fossá, which runs south from its source Systravatn. To the south of Systrafoss runs the glacial river Skaftá.
Both the waterfall and Systravatn take their name from the sisters of the nearby Kirkjubæjar Abbey.
Coordinates: 63°47′9.41″N 18°3′34.71″W / 63.7859472°N 18.0596417°W