Cremorne (Irish: Críoch Mhúrn) is a barony in County Monaghan, Ireland.

Cremorne is known in Irish as Críoch Mhúrn from the Old Irish Crích Mugdornd, border of the Mugdorna (Murnú), a pre-Celtic or early Celtic people who inhabited much of Ulster before being pushed out by the Gailenga.

Up to about AD 800, the Mugdorna territory stretched from Monaghan to the River Boyne at Navan.

O'Hanraghty (O hInnreachtaigh) settled in this barony from Ui Meith Macha in County Louth following the Norman invasion.

The Leslie family is cited in more recent times as Earl of Rothes.