The Marquess of Londonderry is a title in the peerage of the United Kingdom, created in 1816. The title is associated with the Londonderry family, which has historical ties to the city of Londonderry in Northern Ireland. The family has played a significant role in British politics and society, particularly during the 19th century. The current holder of the title is the 9th Marquess of Londonderry, who succeeded in 2012. The family seat is Wellington Park, located in County Durham, England. The Marquessate is part of a larger lineage that includes various other titles, such as the Viscount Castlereagh and Baron Londonderry.