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, sometimes known as "Maurice the mad", is recorded as the 1st Viscount Fermoy David Roche, 2nd Viscount Fermoy (1573–1635) Maurice Roche, 3rd Viscount Fermoy (1597–1670)