Ullern is a borough of the city of Oslo, Norway.

In Norse mythology, Ullr is a god associated with skiing. Although literary attestations of Ullr are sparse, evidence including relatively ancient place-name evidence from Scandinavia suggests that he was a major god in earlier Germanic paganism. Proto-Germanic *wulþuz ('glory') appears to have been an important concept of which his name is a reflex. The word appears as owlþu- on the 3rd-century Thorsberg chape.