Delvin (Irish: Dealbhna) is a barony in north-east County Westmeath, in the Republic of Ireland. It was formed by 1672. It is bordered by County Meath to the east and three other baronies: Fore (to the north–west), Moyashel and Magheradernon (to the south–west) and Farbill (to the south). The largest centre of population is Delvin.