Hvalsey Church (Danish: Hvalsø Kirke) is the ruins of an old Norse church, which is situated in the fjord of Hvalsey (Qaqortukulooq), not far from Qaqortoq, the largest town in the south of Greenland.
The architecture seems very related to similar Norse buildings from the 14th century. The church is in the region which the Norse named Eystribygð, the Eastern Settlement, when the Vikings settled in Greenland in around 985. There are burials under the walls of this church from earlier phases of use but older churches have not been identified at this site. The Hvalsey church is mentioned in several late medieval documents as one of the 10-14 parish churches in the Eastern Settlement. The church was still in use in 1408.
The church ruin is the best preserved building from the Norse period, and is remarkably well built from ashlar stone, which is the reason why it survives. The Icelandic churches from the same period are all gone, because they were mostly built from timber or grass turf.