Corn Hill, also called Carn Hill or Carn Clonhugh (Irish: Carn Clainne Aodha or Sliabh Cairbre), is a hill in County Longford, Republic of Ireland. It lies north of Longford, between Drumlish and Ballinalee, in the parish of Killoe. At 278 metres above sea level, it is the highest hill in the county and has a television mast (Cairn Hill transmission site) on the top which rises 123 metres above the peak of the hill.