In the Old Norse mythical complex, water is the conduit of life, both a barrier between worlds and also a delimiter of the cosmos, and the medium for some of the most well-known and often represented episodes in the myth, from the rivers known as Élivágar that drain into the void at the start of the world, to the flood that drowns the primordial giants, to Thor’s fishing trip and his adventures wading through a river to Jötunheim. Indeed, whilst gods of the sea such as Njörd with his surf-washed toes, Ægir the gold-rich giant, and the nine sisters known as the waves, are personifications of the sea and both its wealth and its dangers, Thor may be the god who most regularly gets his feet wet and contends with the power of water, even draining the sea in a drinking contest to create the tides. It would be easy to understand water, then, as a chaotic force of nature which the protective god Thor helps to tame for humankind, but in fact its destructive power usually derives from the actions of a malevolent being, and water in a ‘pure’ form is rarely encountered. Indeed, the river that causes Thor so much trouble is being flooded by the urine (or menstrual blood) of a giantess upstream; the rivers that feed Ginnungagap are filled with sediment and the poison of serpents; and even the sea is understood as the blood of Ymir which flooded the world and is made salty by two giant women sitting on the seabed and grinding from a mill. Perhaps it is better, therefore, to conceptualise water in the Norse mythical complex as a neutral medium that gains its properties as an elemental force from what is added to it. This paper will draw on my recent retelling of the stories contained in the Prose Edda to identify some of the most important aspects of water in the Norse mythical complex, and to link these with the central conflict between the forces of chaos and the ‘taming’ gods.