The owl is sacred to the Greek goddess of learning, Athena and is even depicted on some Greco-Roman currency as a symbol of status, intelligence and of course, wealth.
In ancient Egyptian, Celtic, and Hindu cultures the symbolic meaning of owl revolved around guardianship of the underworlds, and a protection of the dead.
In this light the owl was ruler of the night and seer of souls. A misunderstanding of this necessary relationship gave the owl some negative associations with death.
It should be clear that the owl was honored as the keeper of spirits who had passed from one plane to another. Often myth indicates the owl accompanying a spirit to the underworld - winging it's newly freed soul from the physical world into the realm of spirit.
A quick-list of owl symbolic meanings:
Native Americans associated the meaning of owl with wisdom, foresight, and keeper of sacred knowledge. This may largely be due to the fact that the owl is a great foreteller of weather conditions. Also its ability to see at night is legend among the Native Americans, and this attribute would be invoked during ceremonies when an oracle of secret knowledge was required.
Similarly, West African and Aboriginal Australian cultures viewed the owl as a messenger of secrets, kin to sorcerers, as well as companions to seers, mystics and medicine people.
During medieval times in western and central Europe it was fabled that owls were actually priestesses (witches) and wizards in disguise. To this day the owl is considered a witch's familiar (an animal soul-spirit linked to a spiritual person via a unique, communicative bond).