Ó Fearghuis
Ó Fearghuis was the name of a Gaelic-Irish medical family from Connacht. The surname is now generally rendered as Fergus.
The family were originally based at Roscam, in Clann Fhergail (between Oranmore and Galway City). In the 13th century they seem to have removed to north Connacht, to what would later become County Mayo. During the 14th-century members of the family created the manuscript which would come to be known as Liber Flavus Fergusiorum. The last member of the family to own it was John Fergus (scholar), who died in Dublin about 1761.