The name Costello in Ireland is of Anglo-Norman origin deriving from the de Nangle family who were based in the Province of Connaught. The family adopted the Gaelic name Mac Oisdealbhaigh and the Sept name eventually became anglicized as Costello. The majority of descendants can still be found in the West of the country.
Mathew Costello and married Ellen O'Ryan in Boston, Massachusetts in 1845. They were both from Tipperary, Ireland.
This Branch consists of many surnames, which include but are not limited to, Finley, O'Ryan, Brewer, Martin, Hileman and Peo.