By the late nineteenth century the ownership of lands in county Sligo rested in the hands of a numerically small and elite group known collectively as ‘landlords’. The longevity of the connection of these families as landlords varied and while the O’Hara’s of Annaghmore were descendants of a Gaelic landowning family, others such as the Wynne, Gore-Booth, Ormsby and Perceval families belonged to the Cromwellian settlements of the seventeenth century. Others, such as the Walkers of Rathcarrick, were successful merchants in Sligo town and estates in the later eighteenth century while the McMunns purchased Bellville at Dromore West as late as the 1860s. Enjoying the economic, social and political benefits that accompanied ownership of the most sought after commodity in Ireland, the landlord class exerted significant and enduring influence and hegemony over both Sligo’s landscape and people. This essay will initially identify those who owned Sligo on the eve of a protracted process, beginning in the 1880s, that resulted in the dissolution of the estate system. The most symbolic inscriptions made by landlords on Sligo’s landscape were the large country houses that functioned as family homes. Surrounded by carefully contrived demesnes, comprising home farms, ornamental gardens and woodlands amongst other features, the mapping of these ‘big houses’ and landscapes highlights their geography at the turn of the twentieth century. A significant number of these houses and demesnes remain today as significant components of the architectural and cultural heritage of Sligo’s contemporary landscape.