Newcastle (Irish: An Caisleán Nua) is a barony in County Wicklow, Ireland.

Newcastle barony is located in eastern County Wicklow, opening onto the Irish Sea.

This was part of O'Byrne (Ó Broin) country after the 12th century, referred to in Gaelic as Crioch Branach.

[1] Below is a list of settlements in Newcastle barony:

This article related to the geography of County Wicklow, Ireland is a stub.