Fartullagh (Irish: Fir Thulach),[1] previously Tyrrells country,[2] is a barony in south–east County Westmeath, in Ireland.

[3] It is bordered by County Offaly to the south and three other baronies: Moycashel (to the west), Moyashel and Magheradernon (to the north) and Farbill (to the north–east).

[3] The barony contains the eastern half of one large lake, Lough Ennell, the remainder is contained within the barony of Moyashel and Magheradernon.

The M6 motorway passes to the south of Rochfortbridge and Tyrrellspass, which, together with the M4, links Dublin with Galway.

[5] Similarly only four of the townlands in the civil parish of Mullingar are in the barony of Fartullagh, the remainder are in the barony of Moyashel and Magheradernon.