The townland name is an anglicisation of the Gaelic placename Cairrig-ín which means ‘A little rock or a rocky surface’. The oldest surviving mention of the name is in a 1790 list of Cavan townlands, where it is spelled Cargin.
It is bounded on the north by Cavanagh & Cranaghan townlands, on the east by Aghavoher townland, on the south by Mullynagolman townland and on the west by Cloncollow townland. Its chief geographical features are Lough Rud, the Rag River and a drumlin hill reaching to 200 feet (61 m) above sea-level. Carrigan is traversed by Slievebrickan lane. The townland covers 104 statute acres, including 4 acres (16,000 m2) of water.
It formed part of the termon lands belonging to Tomregan Roman Catholic Church which were granted to the Protestant Bishop of Kilmore in 1610 as part of the Plantation of Ulster. By a lease dated 6 April 1612 the said bishop granted the lands to Sir Oliver Lambart of Kilbeggan, County Westmeath and Sir Garret Moore, 1st Viscount Moore of Mellifont, County Louth. On 17 July 1639 the bishop re-granted the lands to Charles Lambart, 1st Earl of Cavan. In the 1740s the bishop leased the land to John Jones for 21 years. This lease was renewed to his descendant John Copeland Jones on 20 May 1843. In the 1860s the holder of the lease was David Fielding Jones.
Ambrose Leet's 1814 Directory spells the name as Carrigan with the resident being Mr. Lanauze.
The Tithe Applotment Books for 1827 lists only one tithepayer in the townland- Andrew Lanauze.
The Ordnance Survey Name Books for 1836 give the following description of the townland- Cairrigín, 'a little rock'. 2 miles south of Ballyconnell. Bishop's land, held by Jones in perpetuity. Rent 5 shillings and 6d to bishop. Produces wheat, oats, barley and potatoes. Houses are made of stone.
In 1841 the population of the townland was 17, being 10 males and 7 females. There were three houses in the townland, all were inhabited.
In 1851 the population of the townland was 18, being 11 males and 7 females. There were three houses in the townland, all were inhabited.
In 1861 the population of the townland was 18, being 10 males and 8 females. There were four houses in the townland, all were inhabited.
In 1871 the population of the townland was 6, being 3 males and 3 females. There were three houses in the townland, all were inhabited (page 279 of census).
In 1881 the population of the townland was 5, being 3 males and 2 females. There were two houses in the townland, one of which was uninhabited.
In 1891 the population of the townland was 6, being 4 males and 2 females. There were two houses in the townland, all were inhabited.