In Norse mythology, Sleipnir is Odin's magical eight-legged steed, and the first of all horses. His name means smooth or gliding, hence the English word, "slippery". Loki, in the guise of a mare, gave birth to Sleipnir by Svadilfari.

Loki returned to Asgard and gave the eight-legged gray colt to Odin, telling him that the horse was the swiftest on earth, and could bear Odin over sea, through the air, and to and from the land of the dead. Sleipnir had runes carved on his teeth.

It has been suggested that Sleipnir having eight legs is symbolic of the four men who carry a coffin, i.e. a steed to carry the rider into the underworld. It might also be a reference to a real horse with three toes, a genetic manifestation that occasionally happens on the front or rear legs of a horse, usually without harm to the animal. Though rare, it has been seen, (Julius Caesar rode just such a horse in a number of battles) and this might have worked its way into the myth. Ásbyrgi (literally the fort of the aesir), a place in the northeast of Iceland, is believed to have been created when Sleipnir's hoof touched down.

A stainless steel statue of Sleipnir is a prominent feature in the United Kingdom Midlands town of Wednesbury (which means Odin's fort).

Alternative: Sleipner