From Ó Cionaodha, of disputed root — distinct septs in Galway's Uí Maine and, separately, further east in Meath and Louth.
Gaelic Origin · Root name Cionaodh
Kenny descends from the personal name Cionaodh, whose own meaning isn't fully agreed. Unrelated Ó Cionaodha septs held ground in the Uí Maine territory of east Galway and, separately, further east across Meath and Louth.
A name spread wide enough across the midlands and west that no single sept can claim to be the ‘real’ one — every branch has an equal right to it.
Irish form: Ó Cionaodha