There have been several periods in Irish history when significant numbers of towns were founded in a relatively short time scale, one being the so-called landlord towns of the 18th and 19th centuries. In essence, all towns were landlord towns, as all land was owned by someone, but the degree of involvement of the landlords in town development varied.

In some cases the town arose due to a major government investment in the area, such as the growth of Newbridge after a large army barracks was built, while the development of new towns adjacent to older villages at Dunleary and Dunmore East arose out of the construction of the harbours.

Other towns were built by landlords to house their tenants, but it was also fashionable to have a town, and many were built with picturesque building designs, such as Enniskerry, Castlebellingham and Ardagh. In other cases landlords used towns as a means to improve their estates and perhaps the most active in this line was the 3rd earl of Altamont. He developed the town of Westport in the 1780s and nearby the satellite town of Westport Quay, before going on to found Louisburgh to house refugees from northern Ireland.

Several were built as industrial towns, though in many cases, such as Prosperous, New Birmingham and Stratford-on-Slaney they never reached their founder's ambitions. In others, such as Portlaw and Bessbrook, the industries became extremely large and successful, before collapsing in a later generation.

A number of towns in the west benefited from government schemes to tackle poverty, particularly through programmes of road and pier building. Binghamstown showed an early promise before being overshadowed by Belmullet after roads reached that area in the 1820s. Roundstone was developed by Alexander Nimmo, the engineer responsible for the development of the western district, also in the 1820s.

The town of Ballydesmond, formerly King William's Town, on the Cork border with Kerry, was built by the crown as a model of how landlords might develop towns on their estates, and this also arose from the government scheme to improve road communications through the less developed regions.