A ghost estate is an unoccupied housing estate, particularly one built in the Republic of Ireland during the period of economic growth when the Irish economy was known as the Celtic Tiger. A massive surplus of housing, combined with the late-2000s recession, resulted in a large number of estates being abandoned, unoccupied or uncompleted. The National Institute for Regional and Spatial Analysis defines a ghost estate as developments of "ten or more houses where 50% of the properties are either vacant or under-construction", which therefore does not fully cover the total number of unfinished estates.

A housing estate is a group of homes and other buildings built together as a single development. The exact form may vary from country to country.