Ó Siadhail

Ó Siadhail is a Gaelic-Irish surname.

There were at least three families of this name in Gaelic Ireland.

Little is recorded of the Ui Maine family. Those of Uí Failghe and Tír Chonaill were ollamhs of medicine, hereditary physicians to the ruling families in the respectives kingdoms and environs. It is not clear if the two were branches of the one family, or unrelated families who happened to bear the same surname.

The surname is now generally anglicised as O'Shiel, Shiel, Sheil, Sheils, Sheals, Sheal and Sheilds (or Shiels and Shields), but the original form, Ó Siadhail, is used by Gaeilgeoirs.

Notable people named Ó Siadhail or one of its variants include:

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