Yes it is.
the name Sullivan is indeed irish. and so is the name McGann. and OHalloran. and many other last name that start with a sub name. that is why we ask such questions. names like Sullivan are rare to be Irish.
Irish
Suil Amhain is Irish for Sullivan. translated back to English it means One Eye
Ireland. Originally O'Sullivan, Ó Súilleabháin in Irish, they were mainly fromCo. Cork and Co. Kerry.
http://www.zelo.com/firstnames/findresults.asp?name=SULLIVAN
There is no Irish version of the name.
Irish
Suil Amhain is Irish for Sullivan. translated back to English it means One Eye
O'Sullivan = Ó Súilleabháin
she is
Harry Sullivan - footballer - was born on 1933-04-08.
Ireland. Originally O'Sullivan, Ó Súilleabháin in Irish, they were mainly fromCo. Cork and Co. Kerry.
Sullivan or O'Sullivan is an Irish surname. It was originally spelled Ó Súileabháin in the Irish language ("Gaelic"). It is thought to derive from Súldubán (dark-eyed).
Becky Sullivan's birth name is Rebecca Sullivan.
Reebie Sullivan's birth name is Rebecca Sullivan.
Angila Sullivan's birth name is Angela Marie Sullivan.
Barry Sullivan's birth name is Sullivan, Patrick Barry.
Deirdre Sullivan's birth name is Catherine R. Sullivan.