Sligo is probably one of the most ancient communities in Ireland. A causewayed enclosure at Maugheraboy on the fringe of the town has been dated to over 6000 years old; such structures are typically indicative of a Neolithic village, and the massive building projects of Carrowmore and Knocknarea may well have been undertaken by the inhabitants of this settlement. Ancient communities made use of the rich beds of oysters along the coast, and the profusion of shell heaps deposited by them in the area lent the name Sligeach, or 'shelly place' to the town and the county. The medieval walled town of Sligo has its origins in Norman times, when the Castle and Dominican Friary (known as Sligo Abbey ( was built. One of the most visited locations by Sligo tourists, the Abbey dates to the middle of the thirteenth century, when it was constructed by the Lord Chief Justice of Ireland as a place of worship.

This place is of historical importance in part because it was twice destroyed and rebuilt, making it something of a symbolic phoenix for Sligo.  It was first destroyed at the beginning of the fifteenth century.  It was destroyed again in the middle of the seventeenth century. From the fifteen hundreds forward, Sligo was a bustling port town, with many businesses nestled in its narrow streets. Times of prosperity and of great trouble ebbed and flowed; imports like wine and timber were delivered, but famine and fever were regular visitors. Some of these stories inspired Bram Stoker in writing Dracula. 

Changes made in the nineteenth century are still visible today, much of the town walls were destroyed and a number of large warehouses consructed. Roads were improved and widened, and the old access road over Harmony Hill was replaced by the modern road known today as Pearse Road. The area around Sligo was commemorated in writing by the poet W.B. Yeats at the beginning of the twentieth century.  Another famous association with Sligo is through Spike Milligan whose father was born in Holborn Street.