Ukonkivi is a sacred Sami site located on Ukonsaari (also called Äijih), a rocky island with steep cliffs that rises out of the middle of Lake Inari in northern Lapland. Ukonkivi was an important seita, or sacred natural formation, to the local Inari Sami and was used as a sacrificial site and place of worship, thought to be actively used even up to the 19th century. One of Lapland's most important archaeological finds occurred here in 1873 by Sir Arthur Evans, a British archaeologist, who found silver jewelry remnants in one of the islands caves. A second seita was discovered on the island by Finnish archeologists in 2007.

The island is roughly 300 metres long, 100 metres wide, and over 30 metres high, standing out noticeably amongst other nearby islands within the lake. There is a dock on the western shore of Ukonsaari from where a set of steps leads to the top of the island, where visitors can get a 360 degree view of the surrounding area.

Ukonsaari is about 11 kilometers from Inari village and in summer, visitors can catch guided tours by boat to the island from the harbor near the Siida museum. The island can also be reached in winter time when the lake is frozen.

Ukonkivi has been nominated as a UNESCO World Heritage Site.