Welsh tower houses were fortified stone houses that were built between the early 14th and 15th centuries. They are related to tower houses, which occur in considerable numbers in Ireland and Scotland and to a much lesser extent in England. A map showing the distribution of tower houses within the United Kingdom is given in Houses of the Welsh Countryside.

Tower houses appeared on the Islands of Ireland and Great Britain starting from the High Middle Ages. They were constructed in the wilder parts of Great Britain and Ireland, particularly in Scotland, and throughout Ireland, until at least up to the 17th century. The remains of such structures are dotted around the Irish and Scottish countryside, with a particular concentration in the Scottish Borders where they include peel towers and bastle houses. Some are still intact and even inhabited today, while others stand as ruined shells.