The Irish name Sheehan means peaceful, graceful or courteous. It is an Anglicized form of the Gaelic "Siodhachain" and a diminutive of "Siodhach" or "Siodach."
Sheehan, along with the variant Sheahan, is the 75th most common surname in Ireland, originating in County Clare and concentrated most heavily in Clare, Cork, Kerry and Limerick counties. In the United States, Sheehans are found in the greatest numbers in the states of California, Illinois, Massachusetts, New York and Pennsylvania.
The Sheehan family coat of arms features a silver dove with an olive branch in its beak, representing and reinforcing the association of the Sheehan name with peace.