Kiltimagh (Irish: Coillte Mach) is a town in County Mayo in Ireland. As of the 2022 census, the town had a population of 1,232 people. Although there is no river going through the town, three rivers flow around the town: the Glore River, Yellow River and Pollagh River. The town centre sits at the crest of a hill surrounding The High Fort (Mooney's Fort/Lios Ard) in Fortlands and built out linearly on the main road from there.

The town's name, in the Irish language, was originally Coillte Maghach (the woods of Maghach), based on a reputed association with a chieftain of the Fir Bolg named Maghach. Over the years this then became what it is today, Kiltimagh (Irish: Coillte Mach).

Kiltimagh is part of the barony of Gallen.

The lands around Kiltimagh were granted to the Ormsby family by patents dated 6 April and 6 July 1677. The Ormsbys, who originally came from Louth, Lincolnshire, had resided in the area prior to 1677 and had purchased land from transplanted persons.

Prior to the arrival of the Ormsbys, the lands around Kiltimagh had been mainly owned by the Anglo-Norman Jordan (De Exeter) family. In Speed's Theatre of Great Britain and Ireland (1676), the lands of the Septs of Connaught are recorded as being confiscated including that of the territory of MacJordan near to Kiltimagh.

As late as 1876, Anthony Ormsby of Ballinamore is recorded as owning 4,492 acres in the area.

One of the first large modern structures to be constructed in the locality was the home of Thomas Ormsby (1738-1822), Ballinamore House which was extant from around 1777. In 1836, works are recorded as being carried out at the house by Thomas Murphy for the owner Thomas Ormsby. The house was owned by members of the Ormsby family until it was sold in 1936. As of 2023, the building operates as a nursing home.

From the late 19th century, Kiltimagh began to develop as more of a market town.