Lonely Planet's Ireland guide states that Monaghan's residents live their lives utterly unaffected by tourism! County Monaghan is located within the province of Ulster and is part of the Republic of Ireland. The name derives from the Irish word muine meaning "brake" (a thickly overgrown area) or sometimes "hillock". The county council's preferred interpretation is "land of the little hills", a reference to the numerous drumlins in the area. These are gentle whale-shaped hills created by the movement of ice during the last Ice Age and they often appear in collections of hills with the same shape, size and orientation. Due to the undulating countryside and the absence of mountains, only a few drumlins are higher than 300 metres.

In 1585, Sir John Perrot,Lord Deputy of Ireland during the time of Elizabeth 1st, visited the area and met with the Irish chieftains. They requested that Ulster be divided into counties and land in the kingdom of Oriel be apportioned to the McMahon chiefs. A commission was established to accomplish this and County Monaghan came into being. The County was subdivided into five baronies. After the defeat of the rebellion the Ulster chieftains in 1603, the county was not planted like the other counties of Ulster. The lands were instead left in the hands of the native chieftains. In the Irish Rebellion of 1641 the McMahons and their allies joined the general rebellion of Irish Catholics, and following their defeat there was some plantation of the county with Scottish and English families.

County Monaghan is twinned with the Province of Prince Edward Island in Canada. At least 20% of the population of Prince Edward Island can trace ancestry to Co Monaghan as a result of migration from Monaghan to that part of Canada during the years 1820-1840. It also has links with Gheel in Belgium, as a result of the martyrdom there in the 5th century of St Dymphna, a local Monaghan saint who is regarded as Patroness of those with mental illness.

Monaghan is the birthplace of the poet and writer Patrick Kavanagh, who based much of his work in the county. Kavanagh is one of the most significant figures in 20th century Irish Poetry. County Monaghan has been home to many distinguished and talented personages over the years including Barry McGuigan, a 1985 world boxing champion, E.P. Shirley, the writer and antiquarian and the writer and polictican Charles Gavan Duffy, who was a co-founder of The Nation with Thomas Davis before holding the post of Premier of Victoria, Australia. Ardal O’Hanlon aka father Dougal in Father Ted is a native of Carrickmacross in Co.Monaghan.