If one looks at early-Medieval Scandinavian literature, we find many examples of old genealogies that mention various Gods, including Óðinn, as being the ancestor of one or more noble families.
Then, if we go back even further, to the 1st century B.C, the Roman author Tacitus also mentions that some Germanic tribes thought of themselves as the direct descendants of some older Deity.
As for the historical truth, well, Thor Heyerdahl who was a Norwegian archeologist believed that Óðinn was an actual human king who migrated to Scandinavia in the Iron Age
Not in the material world as the figure described in mythology. It is pretty difficult for people to actually shapeshift or travel to other worlds these days, except in the realm of non-physical reality.
Snorri Sturlason is the Icelandic warrior, poet, and politician who wrote down the most comprehensive account of Norse mythology called The Younger Edda. In his preface he states that Odin was an ancient king who led his people to settle in Scandinavia, and he probably believed that. During the transition between Paganism and Christianity many lovers of traditional lore said that the ancient gods were really once humans, generally saying they were magical people. (This process is called Euhemerism, after the Greek Euhemeris who popularized it in his ancient time.)
Since some myths and legends have been proven to have a kernel of historical truth to them, it opens the possibility that Odin actually existed. But we have no actual proof of that—just myths—so you will have decide what level of truth is acceptable to you...read more>>>...