The Clan/Sept History

The old Gaelic name used by the O Sullivan family in Ireland was O Suileabhain,
which is partially derived from the word "suil," which means "eye." The surname
probably means either one-eyed or hawk-eyed.

Spelling variations of this family name include: O'Sullivan, Sullivan and
others.
First found in county Tipperary.
Some of the first settlers of this family name or some of its variants were:
Andrew, Arthur, Daniel, Denis, John, Michael, Patrick, Simon, Timothy and
William O'Sullivan, who all arrived in Philadelphia between 1840 and 1860; Anne,
Bridget, Cornelius, Daniel, Denis, Ellen, James, Jeremiah, John, Julia, Mary,
Owen, Patrick, Terence and William Sullivan all arrived in Boston in 1849.