Tierney /ˈtɪərni/ is an Irish surname, and a female given name.
The name is an Anglicized form of the Irish language surname Ó Tiarnaigh (literally "Descendant of Tiarnach"; historically spelt Ó Tighearnaigh), derived from tiarna, the Irish word for 'lord' or 'master'. It is sometimes a variant of Tiernan (Irish: Mac Tiarnáin).[1]