Roscommon (Irish: Ros Comáin, meaning "Saint Coman's wood") is the county town of County Roscommon in Ireland. Its population at the 2006 census was 5,017 (including rural area). The town is near the meeting of the N60, N61 and N63 roads.

The name Roscommon is derived from Coman mac Faelchon who built a monastery there in the 5th century. The woods near the monastery became known as Saint Coman's Wood (Ros Comáin). This was later anglicised to Roscommon. The town is the location of a notable archaeological find in 1945 when a lunula, a gold necklace, and two discs were discovered. Both items are dated to the period 2,300 and 1,800 BC.

It was the homeland of the Connachta dynasty, and included such kingdoms as Uí Maine, Delbhna Nuadat, Síol Muirdeach, and Moylurg. In addition, it contained areas known as Trícha cét's, Túath and is the homeland of surnames such as Ó Conchobhair (O'Connor), Mac Diarmada (McDermott), Ó Ceallaigh (Kelly), Ó Birn (Beirne, Byrne, Burns), Mac Donnchadha (McDonough) and Brennan (Mac Branáin and Ó Branáin).

County Roscommon (Irish: Contae Ros Comáin) is a county in Ireland. It is located in the West Region and is also part of the province of Connacht. It is named after the town of Roscommon. Roscommon County Council is the local authority for the county. The population of the county is 63,896 according to the 2011 census.

Roscommon is the 11th largest of the 32 counties of Ireland by area and the fifth least-populous county in Ireland. It has the second least population density after Leitrim. It is the third largest of Connacht’s five counties by size and fourth largest in terms of population. The county borders every other Connacht county (Galway, Mayo, Sligo and Leitrim). In 2008, a news report said that statistically, Roscommon has the longest life expectancy of any county on the island of Ireland.Lough Key in north Roscommon is noted for having thirty-two islands. The Geographical centre of Ireland is located in the county.

Roscommon comes from the Irish Ros meaning a wooded, gentle height and Comán, the name of the county's famous saint and the first bishop of the see. Rathcroghan was home to the Kings of Connacht and then to the High Kings of Ireland.