Truskmore (Irish: Trosc Mór, meaning "big cod") is a 647 m (2,123 ft) mountain on the border of County Sligo and County Leitrim in Ireland. It is the highest peak of the Dartry Mountains and the highest in County Sligo. Truskmore is the highest point on a large plateau stretching across northeast Sligo and northwest Leitrim. The edges of this plateau is marked by high cliffs—these include Ben Bulbin (526m), Benwiskin (514m), Slievemore (597m) and Kings Mountain (462m). The peak of Truskmore is in County Sligo, a short distance from the border with County Leitrim. However, the mountain itself is within both counties.
The Truskmore television transmitter opened on 1 February 1962 and was the second of the original five main Telefis Éireann transmitters to go on air. Initially its transmissions were only in 405 lines on VHF channel 11, with 625 lines transmissions beginning in 1963. VHF FM radio was added in 1966. In 2009 a new 175m mast was constructed in preparation for the change over to digital television transmission and the original 1961 mast removed. Since the national shut down of the analogue television networks on 24 October 2012, Truskmore now broadcasts the Irish DTT service Saorview and the national FM radio channels to the North West of Ireland, including a large area of the West of Northern Ireland. It is owned and operated by 2RN, a subsidiary of the Irish public service broadcaster RTÉ.