One branch of the family who served in the army of the Austrian Empire lived at Newcastle, near Swineford, Co Mayo at the end of the 18th century.
Estates:
Sir Charles O'Hara, created Baron Tyrawley in 1706, and his son James 2nd Baron both had distinguished military careers in the wars on the continent of Europe in the 18th century. The title became extinct with the death of the 2nd Baron in 1774.
Estates:
The Kilboyne, Spencer Park and Newcastle branches of the O'Malley family were descended from Owen O'Malley of Burrishoole (1650-1738)and his wife Martha Browne of the Neale.
Estates:
The descendants of the Reverend John O'Rorke, a Protestant clergyman, who acquired land in the Tuam area of county Galway. Lady Molly Cusack Smith,the first lady Master of the Galway Blazers,was a member of this family.
Estates:
James O'Sullivan married Mary Moore one of the co heiresses of the Moore estate in the parish of Drum, barony of Athlone, county Roscommon, in the mid 18th century. They had one son John, who had 3 sons James, Patrick and John. Patrick married Jane De Burgh in 1802 and his younger brother John married Dorothea Delaney.
Estates:
The Ormes settled in the parish of Crossmolina early in the 18th century. A younger son of this branch of the Orme family married into the Knoxes of Rappa and lived at Glenmore, Crossmolina. His sisters married Samuel Handy and Godfrey Fetherstonhaugh.
Estates:
Elizabethan settlers located at first in county Sligo, from where they spread into counties Mayo, Roscommon and Galway. The Ballinamore branch were descended from the Ormsby of Comyn or Cummin in county Sligo.
Estates: