Mahoney is an Irish surname originally designating the descendants of Mathghamhain.
In the early 16th century, during the collapse of the O'Mahonys, three new breakaway dynastic families formed: MacMahon, Mahon and Mahoney (the latter bearing an earldom.
Extinct c. 1815).
It is often mispronounced as ma-ho-nee its true Irish pronunciation is actually marr-nee.