Killarah (from Irish: Coill an Rátha is a townland in the civil parish of Kildallan, barony of Tullyhunco, County Cavan, Ireland.
Killarah is bounded on the west by Bellaheady, Coologe and Toberlyan Duffin townlands, on the east by Agharaskilly, Clontygrigny and Fartrin townlands, on the south by Callaghs townland and on the north by Crossmakelagher and Cormeen townlands. Its chief geographical features are Bellaheady Mountain which rises to 328 feet, Lough Andoul (Loch an Diabhail = The Devil’s Lake), the Shannon-Erne Waterway, small streams, forestry plantations, sand pits, gravel pits and dug wells. Killarah is traversed by minor public roads and rural lanes. The townland covers 688 acres.
Until the 1650s Killarah was paired with the townland of Bellaheady. Locals and the Ordnance Survey still refer to part of Killarah as Bellaheady Mountain.
The townland was occupied in prehistoric times as is evident from the number of cairns therein.
In medieval times the land belonged to the McKiernan Clan.
The Plantation of Ulster 1609 Baronial Map depicts the townland as Rosbrazill.
The 1652 Commonwealth Survey lists the townland as Killarah.
The 1665 Down Survey map depicts it as Rossepressell.
William Petty's map of 1685 depicts it as Rosspressell.
In the Plantation of Ulster by grant dated 23 June 1610, along with other lands forming the Manor of Calva, King James VI and I granted one poll of Rossebrissell otherwise Killara to Hugh Culme. In the same year Culme surrendered his interest to Walter Talbot of Ballyconnell. In an inquisition of King Charles I held at Cavan on 20 September 1630, it stated that James Talbott of Beallaconnell owned the townland of Rosbreassell alias Killarra, containing one poll, having received it as part of the Ballyconnell estate on the death of his father Walter Talbot on 26 June 1625. Talbot’s land was taken over by rebels during the Irish Rebellion of 1641. At Cavan on 26 July 1642 Thomas and William Jones gave the names of rebel leaders in Cavan, including Owen Mc William of Rosbreske, Donogh Mc Kernan of same and William Mc Kernan of same. After the rebellion concluded, the land was confiscated in the Cromwellian Settlement and the 1652 Commonwealth Survey lists the townland as belonging to Lieutenant-Colonel Tristam Beresford and by a further confirming grant from King Charles II on 6 November 1666, the lands of Rospressell containing 2 poles or 431 acres & 31 perches was granted to the aforementioned Sir Tristram Beresford, 1st Baronet at an annual rent of £5-16s-5d. On the 11 September 1670 Respressol was created as part of the Manor of Beresford. The Hearth Money Rolls of 1664 list five taxpayers in the townland- John Hakins, Philip Reilly, Philip O'Mane, Shane McLaghlyn & Tirlagh O'Cuillin.