Delvin is a village approximately 20km from Mullingar town.

Delvin has a population of 774(2016)

Delvin (Irish: Dealbhna or Dealbhna Mhór) is a town in County Westmeath, Ireland; it is located on the N52 road at a junction with the N51 to Navan.

The word Delvin comes from Delbhna. That tribe settled in what is present-day Delvin, along with a branch of the Soghain, in Tricha céd na Delbna Móire agus na Sogan.

Delvin Castle (or Nugent Castle), now a ruin, was built in 1181 by Hugh de Lacy, Lord of Meath for his brother-in-law, Gilbert de Nugent. De Nugent came to Ireland with de Lacy in 1171 and settled on some land in Delvin. De Nugent was granted the title Baron of Delvin within the Lordship of Meath, a title now held by the Earl of Westmeath. The ruins of Nugent Castle (not publicly accessible) remain near the center of the town.

A second castle was built several centuries later, hundreds of metres from the centre of the Delvin settlement of that time. This building, known as Clonyn Castle, is situated south of Delvin between the N52 and the Collinstown road. Built in the mid-19th century, by Lord and Lady Greville Nugent, it was sold by the Nugent family in 1922. Changing hands several times during the 20th century, it is now a private residence.