Viscount Fermoy was a title in the Peerage of Ireland. The title had a number of creations. Holders of the title, including members of the Roche family of Blackwater Castle in Castletownroche in County Cork, included:
Maurice Roche (or De Rupe), sometimes known as "Maurice the mad", is recorded as the 1st (and sometimes 6th) Viscount Fermoy (âÂÂ1600)