In Norse mythology, Garmr or Garm (Old Norse: Garmr [ˈɡɑrmz̠]) is a wolf or dog associated with both Hel and Ragnarök, and described as a blood-stained guardian of Hel's gate.

The etymology of the name Garmr remains uncertain. Bruce Lincoln brings together Garmr and the Greek mythological dog Cerberus, relating both names to a Proto-Indo-European root *ger- "to growl" (perhaps with the suffixes -*m/*b and -*r). However, Daniel Ogden notes that this analysis actually requires Cerberus and Garmr to be derived from two different Indo-European roots (*ger- and *gher- respectively), and in this opinion does not establish a relationship between the two names.

He also appears in Low Saxon folklore as the helhond or kardoes in Twente, Eastern Netherlands as the companion of Tamfana or Tanfana; one of Hell's/Nerthus's many titles/names.

It's said that his red glowing eyes have been seen around the tankenberg, in Oldenzaal and that his howl indicates illness and death.

Elements within pan-Germanic folklore overlap with the ancient tradition of "'t an bloaz'n" of the "mirreweenterhorn", blowing the midwinterhoorn, also called a Lur.

It is likely that the eery sounds of the horn, used to communicate with the spirits of the ancestors, were answered by wolves in the area, and thus the sound became synonymous to winter, illness, death and the veil between life and death being very thin.

The Lur/midwinterhorn was a ritual animistic tool, played to call into the "otherworld", thank the ancestors or to announce and guide the passing of family and members of the community.

The Poetic Edda poem Grímnismál mentions Garmr: