In Norse mythology, Gefjun ("giver"; also Gefjon, Gefyon, Gefn) was a seeress and goddess, a member of both the Vanir and the Aesir. All women who die virgin are sent to her hall, and thus she is characterised as a goddess of virtue, yet she was also a fertility goddess.

Moreover, "Gefn" is one of the alternate names of Freyja, the Norse goddess of procreation. It is entirely conceivable that Gefjun is merely an aspect of Freyja in the same way that Morrigan in Irish mythology has a multiplicity of aspects.

She was associated with the plow, virgins and good luck. Girls who died as virgins became her servants in the afterlife.

Her husband was King Skjöld, son of Óðinn. Many legendary Danish kings claimed to be descended from her.

Having been promised as much land as she could plow in one night, she transformed her four sons into oxen and took enough land to create the Danish island of Zealand, leaving the Swedish lake Mälaren. However, some claim that the legend originally referred to Vänern - which in its outline resembles Zealand. This legend is commemorated by the bronze Gefjun fountain in Copenhagen sculpted by Anders Bundgaard in 1908.

The goddess's name is shared with a Norse term meaning "marriage", represented by the English language as "give", meaning "wife" (see dowry), and found in the form of a Rune.