Dorwinion or Dor-Winion, the "Land of Wines", is a land which lay on the northwestern shores of the Sea of Rhûn.
It is also mentioned in the Narn i Chîn Húrin, where it was drunk in Thingol's halls of Menegroth. It is said there to lie in the "Burning south", which might suggest it was a different "Dorwinion", or may just have referred to the fact it came from the more southern lands of Rhovanion by way of the Dwarf-road of Beleriand.
In Dorwinion was made a heady wine, which was strong enough to let even Elves get drunk and fall asleep.
Not much else is known about Dorwinion, and the name cannot easily be translated. It is not even known if the name is true Sindarin.
It has been suggested by Tolkienists that the name may not have been Sindarin at all, but come from an Avari or Nandorin tongue. If that is the case Dorwinion may have been the only Avari realm close to those areas of Middle-earth that Tolkien's stories take place. Certainly the element Winion, apparently meaning "wine", has no probable origin in any known etymology. Support for the Elven origin of Dorwinion is that its population must have been Elvish, since it was already well established while the Atanatári were still young.