KeirnanIrish Gaelic form of Keirnan is Mac Thighearnain, which is derived from the word tighearna, meaning "lord." First found in County Cavan, Ireland.
KeirseyIrish Topographic name of Norman origin name dating back to the 13th century.
KelleherIrish From Gaelic Ó Céileachair meaning "son of Céileachar". The Irish given name Céileachar means "companion-dear", i.e., "lover of company".
KilcommonIrish Indicated a person who was from Kilcommon, Erris, County Mayo in Ireland. The place name Kilcommon derives from the Gaeltacht phrase Cill Chomáin, meaning "church of St. Comán."
KileyIrish, English Anglicized form of the Old Gaelic "O' Cadhla" meaning "son of Cadhla". Cadhla means meaning graceful or beautiful; hence, "descendant(s) of 'the graceful one'".
KilgallenIrish Kilgallen comes from the Irish name Mac Giolla Chaillin, meaning the son of a servant or devotee of St. Caillin.
KilleenIrish From the Gaelic name Ó Cillín meaning "descendant of Cillín".
KirwanIrish From Gaelic Ó Ciardhubháin meaning "descendant of Ciardhubhán", a given name composed of the elements ciar "dark" and dubh "black" combined with a diminutive suffix.
KnowlesIrish As an Irish surname it is an anglicized form of Gaelic Ó Tnúthghail meaning "descendant of Tnúthgal", a given name composed of the elements tnúth "desire, envy" and gal "valor".